what fetal presentation means

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Breech, posterior, transverse lie: What position is my baby in?

Fetal presentation, or how your baby is situated in your womb at birth, is determined by the body part that's positioned to come out first, and it can affect the way you deliver. At the time of delivery, 97 percent of babies are head-down (cephalic presentation). But there are several other possibilities, including feet or bottom first (breech) as well as sideways (transverse lie) and diagonal (oblique lie).

Fetal presentation and position

During the last trimester of your pregnancy, your provider will check your baby's presentation by feeling your belly to locate the head, bottom, and back. If it's unclear, your provider may do an ultrasound or an internal exam to feel what part of the baby is in your pelvis.

Fetal position refers to whether the baby is facing your spine (anterior position) or facing your belly (posterior position). Fetal position can change often: Your baby may be face up at the beginning of labor and face down at delivery.

Here are the many possibilities for fetal presentation and position in the womb.

Medical illustrations by Jonathan Dimes

Head down, facing down (anterior position)

A baby who is head down and facing your spine is in the anterior position. This is the most common fetal presentation and the easiest position for a vaginal delivery.

This position is also known as "occiput anterior" because the back of your baby's skull (occipital bone) is in the front (anterior) of your pelvis.

Head down, facing up (posterior position)

In the posterior position , your baby is head down and facing your belly. You may also hear it called "sunny-side up" because babies who stay in this position are born facing up. But many babies who are facing up during labor rotate to the easier face down (anterior) position before birth.

Posterior position is formally known as "occiput posterior" because the back of your baby's skull (occipital bone) is in the back (posterior) of your pelvis.

Frank breech

In the frank breech presentation, both the baby's legs are extended so that the feet are up near the face. This is the most common type of breech presentation. Breech babies are difficult to deliver vaginally, so most arrive by c-section .

Some providers will attempt to turn your baby manually to the head down position by applying pressure to your belly. This is called an external cephalic version , and it has a 58 percent success rate for turning breech babies. For more information, see our article on breech birth .

Complete breech

A complete breech is when your baby is bottom down with hips and knees bent in a tuck or cross-legged position. If your baby is in a complete breech, you may feel kicking in your lower abdomen.

Incomplete breech

In an incomplete breech, one of the baby's knees is bent so that the foot is tucked next to the bottom with the other leg extended, positioning that foot closer to the face.

Single footling breech

In the single footling breech presentation, one of the baby's feet is pointed toward your cervix.

Double footling breech

In the double footling breech presentation, both of the baby's feet are pointed toward your cervix.

Transverse lie

In a transverse lie, the baby is lying horizontally in your uterus and may be facing up toward your head or down toward your feet. Babies settle this way less than 1 percent of the time, but it happens more commonly if you're carrying multiples or deliver before your due date.

If your baby stays in a transverse lie until the end of your pregnancy, it can be dangerous for delivery. Your provider will likely schedule a c-section or attempt an external cephalic version , which is highly successful for turning babies in this position.

Oblique lie

In rare cases, your baby may lie diagonally in your uterus, with his rump facing the side of your body at an angle.

Like the transverse lie, this position is more common earlier in pregnancy, and it's likely your provider will intervene if your baby is still in the oblique lie at the end of your third trimester.

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What to know if your baby is breech

What's a sunny-side up baby?

What happens to your baby right after birth

A newborn baby wrapped in a receiving blanket in the hospital.

How your twins’ fetal positions affect labor and delivery

illustration of twin babies head down in utero

BabyCenter's editorial team is committed to providing the most helpful and trustworthy pregnancy and parenting information in the world. When creating and updating content, we rely on credible sources: respected health organizations, professional groups of doctors and other experts, and published studies in peer-reviewed journals. We believe you should always know the source of the information you're seeing. Learn more about our editorial and medical review policies .

Ahmad A et al. 2014. Association of fetal position at onset of labor and mode of delivery: A prospective cohort study. Ultrasound in obstetrics & gynecology 43(2):176-182. https://www.ncbi.nlm.nih.gov/pubmed/23929533 Opens a new window [Accessed September 2021]

Gray CJ and Shanahan MM. 2019. Breech presentation. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK448063/ Opens a new window [Accessed September 2021]

Hankins GD. 1990. Transverse lie. American Journal of Perinatology 7(1):66-70. https://www.ncbi.nlm.nih.gov/pubmed/2131781 Opens a new window [Accessed September 2021]

Medline Plus. 2020. Your baby in the birth canal. U.S. National Library of Medicine. https://medlineplus.gov/ency/article/002060.htm Opens a new window [Accessed September 2021]

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Fetal presentation before birth

The way a baby is positioned in the uterus just before birth can have a big effect on labor and delivery. This positioning is called fetal presentation.

Babies twist, stretch and tumble quite a bit during pregnancy. Before labor starts, however, they usually come to rest in a way that allows them to be delivered through the birth canal headfirst. This position is called cephalic presentation. But there are other ways a baby may settle just before labor begins.

Following are some of the possible ways a baby may be positioned at the end of pregnancy.

Head down, face down

When a baby is head down, face down, the medical term for it is the cephalic occiput anterior position. This the most common position for a baby to be born in. With the face down and turned slightly to the side, the smallest part of the baby's head leads the way through the birth canal. It is the easiest way for a baby to be born.

Head down, face up

When a baby is head down, face up, the medical term for it is the cephalic occiput posterior position. In this position, it might be harder for a baby's head to go under the pubic bone during delivery. That can make labor take longer.

Most babies who begin labor in this position eventually turn to be face down. If that doesn't happen, and the second stage of labor is taking a long time, a member of the health care team may reach through the vagina to help the baby turn. This is called manual rotation.

In some cases, a baby can be born in the head-down, face-up position. Use of forceps or a vacuum device to help with delivery is more common when a baby is in this position than in the head-down, face-down position. In some cases, a C-section delivery may be needed.

Illustration of the head-down, face-up position

Frank breech

When a baby's feet or buttocks are in place to come out first during birth, it's called a breech presentation. This happens in about 3% to 4% of babies close to the time of birth. The baby shown below is in a frank breech presentation. That's when the knees aren't bent, and the feet are close to the baby's head. This is the most common type of breech presentation.

If you are more than 36 weeks into your pregnancy and your baby is in a frank breech presentation, your health care professional may try to move the baby into a head-down position. This is done using a procedure called external cephalic version. It involves one or two members of the health care team putting pressure on your belly with their hands to get the baby to roll into a head-down position.

If the procedure isn't successful, or if the baby moves back into a breech position, talk with a member of your health care team about the choices you have for delivery. Most babies in a frank breech position are born by planned C-section.

Illustration of the frank breech position

Complete and incomplete breech

A complete breech presentation, as shown below, is when the baby has both knees bent and both legs pulled close to the body. In an incomplete breech, one or both of the legs are not pulled close to the body, and one or both of the feet or knees are below the baby's buttocks. If a baby is in either of these positions, you might feel kicking in the lower part of your belly.

If you are more than 36 weeks into your pregnancy and your baby is in a complete or incomplete breech presentation, your health care professional may try to move the baby into a head-down position. This is done using a procedure called external cephalic version. It involves one or two members of the health care team putting pressure on your belly with their hands to get the baby to roll into a head-down position.

If the procedure isn't successful, or if the baby moves back into a breech position, talk with a member of your health care team about the choices you have for delivery. Many babies in a complete or incomplete breech position are born by planned C-section.

Illustration of a complete breech presentation

When a baby is sideways — lying horizontal across the uterus, rather than vertical — it's called a transverse lie. In this position, the baby's back might be:

Down, with the back facing the birth canal.
Sideways, with one shoulder pointing toward the birth canal.
Up, with the hands and feet facing the birth canal.

Although many babies are sideways early in pregnancy, few stay this way when labor begins.

If your baby is in a transverse lie during week 37 of your pregnancy, your health care professional may try to move the baby into a head-down position. This is done using a procedure called external cephalic version. External cephalic version involves one or two members of your health care team putting pressure on your belly with their hands to get the baby to roll into a head-down position.

If the procedure isn't successful, or if the baby moves back into a transverse lie, talk with a member of your health care team about the choices you have for delivery. Many babies who are in a transverse lie are born by C-section.

If you're pregnant with twins and only the twin that's lower in the uterus is head down, as shown below, your health care provider may first deliver that baby vaginally.

Then, in some cases, your health care team may suggest delivering the second twin in the breech position. Or they may try to move the second twin into a head-down position. This is done using a procedure called external cephalic version. External cephalic version involves one or two members of the health care team putting pressure on your belly with their hands to get the baby to roll into a head-down position.

Your health care team may suggest delivery by C-section for the second twin if:

An attempt to deliver the baby in the breech position is not successful.
You do not want to try to have the baby delivered vaginally in the breech position.
An attempt to move the baby into a head-down position is not successful.
You do not want to try to move the baby to a head-down position.

In some cases, your health care team may advise that you have both twins delivered by C-section. That might happen if the lower twin is not head down, the second twin has low or high birth weight as compared to the first twin, or if preterm labor starts.

Landon MB, et al., eds. Normal labor and delivery. In: Gabbe's Obstetrics: Normal and Problem Pregnancies. 8th ed. Elsevier; 2021. https://www.clinicalkey.com. Accessed May 19, 2023.
Holcroft Argani C, et al. Occiput posterior position. https://www.updtodate.com/contents/search. Accessed May 19, 2023.
Frequently asked questions: If your baby is breech. American College of Obstetricians and Gynecologists https://www.acog.org/womens-health/faqs/if-your-baby-is-breech. Accessed May 22, 2023.
Hofmeyr GJ. Overview of breech presentation. https://www.updtodate.com/contents/search. Accessed May 22, 2023.
Strauss RA, et al. Transverse fetal lie. https://www.updtodate.com/contents/search. Accessed May 22, 2023.
Chasen ST, et al. Twin pregnancy: Labor and delivery. https://www.updtodate.com/contents/search. Accessed May 22, 2023.
Cohen R, et al. Is vaginal delivery of a breech second twin safe? A comparison between delivery of vertex and non-vertex second twins. The Journal of Maternal-Fetal & Neonatal Medicine. 2021; doi:10.1080/14767058.2021.2005569.
Marnach ML (expert opinion). Mayo Clinic. May 31, 2023.

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Fetal Presentation, Position, and Lie (Including Breech Presentation)

Key Points |

Abnormal fetal lie or presentation may occur due to fetal size, fetal anomalies, uterine structural abnormalities, multiple gestation, or other factors. Diagnosis is by examination or ultrasonography. Management is with physical maneuvers to reposition the fetus, operative vaginal delivery , or cesarean delivery .

Terms that describe the fetus in relation to the uterus, cervix, and maternal pelvis are

Fetal presentation: Fetal part that overlies the maternal pelvic inlet; vertex (cephalic), face, brow, breech, shoulder, funic (umbilical cord), or compound (more than one part, eg, shoulder and hand)

Fetal position: Relation of the presenting part to an anatomic axis; for transverse presentation, occiput anterior, occiput posterior, occiput transverse

Fetal lie: Relation of the fetus to the long axis of the uterus; longitudinal, oblique, or transverse

Normal fetal lie is longitudinal, normal presentation is vertex, and occiput anterior is the most common position.

Abnormal fetal lie, presentation, or position may occur with

Fetopelvic disproportion (fetus too large for the pelvic inlet)

Fetal congenital anomalies

Uterine structural abnormalities (eg, fibroids, synechiae)

Multiple gestation

Several common types of abnormal lie or presentation are discussed here.

Transverse lie

Fetal position is transverse, with the fetal long axis oblique or perpendicular rather than parallel to the maternal long axis. Transverse lie is often accompanied by shoulder presentation, which requires cesarean delivery.

Breech presentation

There are several types of breech presentation.

Frank breech: The fetal hips are flexed, and the knees extended (pike position).

Complete breech: The fetus seems to be sitting with hips and knees flexed.

Single or double footling presentation: One or both legs are completely extended and present before the buttocks.

Types of breech presentations

Breech presentation makes delivery difficult ,primarily because the presenting part is a poor dilating wedge. Having a poor dilating wedge can lead to incomplete cervical dilation, because the presenting part is narrower than the head that follows. The head, which is the part with the largest diameter, can then be trapped during delivery.

Additionally, the trapped fetal head can compress the umbilical cord if the fetal umbilicus is visible at the introitus, particularly in primiparas whose pelvic tissues have not been dilated by previous deliveries. Umbilical cord compression may cause fetal hypoxemia.

Predisposing factors for breech presentation include

Preterm labor

Uterine abnormalities

Fetal anomalies

If delivery is vaginal, breech presentation may increase risk of

Umbilical cord prolapse

Birth trauma

Perinatal death

Face or brow presentation

In face presentation, the head is hyperextended, and position is designated by the position of the chin (mentum). When the chin is posterior, the head is less likely to rotate and less likely to deliver vaginally, necessitating cesarean delivery.

Brow presentation usually converts spontaneously to vertex or face presentation.

Occiput posterior position

The most common abnormal position is occiput posterior.

The fetal neck is usually somewhat deflexed; thus, a larger diameter of the head must pass through the pelvis.

Progress may arrest in the second phase of labor. Operative vaginal delivery or cesarean delivery is often required.

Position and Presentation of the Fetus

If a fetus is in the occiput posterior position, operative vaginal delivery or cesarean delivery is often required.

In breech presentation, the presenting part is a poor dilating wedge, which can cause the head to be trapped during delivery, often compressing the umbilical cord.

For breech presentation, usually do cesarean delivery at 39 weeks or during labor, but external cephalic version is sometimes successful before labor, usually at 37 or 38 weeks.

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StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-.

StatPearls [Internet].

Delivery, face and brow presentation.

Julija Makajeva ; Mohsina Ashraf .

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Last Update: January 9, 2023 .

Continuing Education Activity

Face and brow presentation is a malpresentation during labor when the presenting part is either the face or, in the case of brow presentation, it is the area between the orbital ridge and the anterior fontanelle. This activity reviews the evaluation and management of these two presentations and explains the role of the interprofessional team in managing delivery safely for both the mother and the baby.

Describe the mechanism of labor in the face and brow presentation.
Summarize potential maternal and fetal complications during the face and brow presentations.
Review different management approaches for the face and brow presentation.
Outline some interprofessional strategies that will improve patient outcomes in delivery cases with face and brow presentation issues.
Introduction

The term presentation describes the leading part of the fetus or the anatomical structure closest to the maternal pelvic inlet during labor. The presentation can roughly be divided into the following classifications: cephalic, breech, shoulder, and compound. Cephalic presentation is the most common and can be further subclassified as vertex, sinciput, brow, face, and chin. The most common presentation in term labor is the vertex, where the fetal neck is flexed to the chin, minimizing the head circumference.

Face presentation – an abnormal form of cephalic presentation where the presenting part is mentum. This typically occurs because of hyperextension of the neck and the occiput touching the fetal back. Incidence of face presentation is rare, accounting for approximately 1 in 600 of all presentations. [1] [2] [3]

In brow presentation, the neck is not extended as much as in face presentation, and the leading part is the area between the anterior fontanelle and the orbital ridges. Brow presentation is considered the rarest of all malpresentation with a prevalence of 1 in 500 to 1 in 4000 deliveries. [3]

Both face and brow presentations occur due to extension of the fetal neck instead of flexion; therefore, conditions that would lead to hyperextension or prevent flexion of the fetal neck can all contribute to face or brow presentation. These risk factors may be related to either the mother or the fetus. Maternal risk factors are preterm delivery, contracted maternal pelvis, platypelloid pelvis, multiparity, previous cesarean section, black race. Fetal risk factors include anencephaly, multiple loops of cord around the neck, masses of the neck, macrosomia, polyhydramnios. [2] [4] [5]

These malpresentations are usually diagnosed during the second stage of labor when performing a digital examination. It is possible to palpate orbital ridges, nose, malar eminences, mentum, mouth, gums, and chin in face presentation. Based on the position of the chin, face presentation can be further divided into mentum anterior, posterior, or transverse. In brow presentation, anterior fontanelle and face can be palpated except for the mouth and the chin. Brow presentation can then be further described based on the position of the anterior fontanelle as frontal anterior, posterior, or transverse.

Diagnosing the exact presentation can be challenging, and face presentation may be misdiagnosed as frank breech. To avoid any confusion, a bedside ultrasound scan can be performed. [6] The ultrasound imaging can show a reduced angle between the occiput and the spine or, the chin is separated from the chest. However, ultrasound does not provide much predicting value in the outcome of the labor. [7]

Anatomy and Physiology

Before discussing the mechanism of labor in the face or brow presentation, it is crucial to highlight some anatomical landmarks and their measurements.

Planes and Diameters of the Pelvis

The three most important planes in the female pelvis are the pelvic inlet, mid pelvis, and pelvic outlet.

Four diameters can describe the pelvic inlet: anteroposterior, transverse, and two obliques. Furthermore, based on the different landmarks on the pelvic inlet, there are three different anteroposterior diameters, named conjugates: true conjugate, obstetrical conjugate, and diagonal conjugate. Only the latter can be measured directly during the obstetric examination. The shortest of these three diameters is obstetrical conjugate, which measures approximately 10.5 cm and is a distance between the sacral promontory and 1 cm below the upper border of the symphysis pubis. This measurement is clinically significant as the fetal head must pass through this diameter during the engagement phase. The transverse diameter measures about 13.5cm and is the widest distance between the innominate line on both sides.

The shortest distance in the mid pelvis is the interspinous diameter and usually is only about 10 cm.

Fetal Skull Diameters

There are six distinguished longitudinal fetal skull diameters:

Suboccipito-bregmatic: from the center of anterior fontanelle (bregma) to the occipital protuberance, measuring 9.5 cm. This is the presenting diameter in vertex presentation.
Suboccipito-frontal: from the anterior part of bregma to the occipital protuberance, measuring 10 cm
Occipito-frontal: from the root of the nose to the most prominent part of the occiput, measuring 11.5cm
Submento-bregmatic: from the center of the bregma to the angle of the mandible, measuring 9.5 cm. This is the presenting diameter in face presentation where the neck is hyperextended.
Submento-vertical: from the midpoint between fontanelles and the angle of the mandible, measuring 11.5cm
Occipito-mental: from the midpoint between fontanelles and the tip of the chin, measuring 13.5 cm. It is the presenting diameter in brow presentation.

Cardinal Movements of Normal Labor

Neck flexion
Internal rotation
Extension (delivers head)
External rotation (Restitution)
Expulsion (delivery of anterior and posterior shoulders)

Some of the key movements are not possible in the face or brow presentations.

Based on the information provided above, it is obvious that labor will be arrested in brow presentation unless it spontaneously changes to face or vertex, as the occipito-mental diameter of the fetal head is significantly wider than the smallest diameter of the female pelvis. Face presentation can, however, be delivered vaginally, and further mechanisms of face delivery will be explained in later sections.

Indications

As mentioned previously, spontaneous vaginal delivery can be successful in face presentation. However, the main indication for vaginal delivery in such circumstances would be a maternal choice. It is crucial to have a thorough conversation with a mother, explaining the risks and benefits of vaginal delivery with face presentation and a cesarean section. Informed consent and creating a rapport with the mother is an essential aspect of safe and successful labor.

Contraindications

Vaginal delivery of face presentation is contraindicated if the mentum is lying posteriorly or is in a transverse position. In such a scenario, the fetal brow is pressing against the maternal symphysis pubis, and the short fetal neck, which is already maximally extended, cannot span the surface of the maternal sacrum. In this position, the diameter of the head is larger than the maternal pelvis, and it cannot descend through the birth canal. Therefore the cesarean section is recommended as the safest mode of delivery for mentum posterior face presentations.

Attempts to manually convert face presentation to vertex, manual or forceps rotation of the persistent posterior chin to anterior are contraindicated as they can be dangerous.

Persistent brow presentation itself is a contraindication for vaginal delivery unless the fetus is significantly small or the maternal pelvis is large.

Continuous electronic fetal heart rate monitoring is recommended for face and brow presentations, as heart rate abnormalities are common in these scenarios. One study found that only 14% of the cases with face presentation had no abnormal traces on the cardiotocograph. [8] It is advised to use external transducer devices to prevent damage to the eyes. When internal monitoring is inevitable, it is suggested to place monitoring devices on bony parts carefully.

People who are usually involved in the delivery of face/ brow presentation are:

Experienced midwife, preferably looking after laboring woman 1:1
Senior obstetrician
Neonatal team - in case of need for resuscitation
Anesthetic team - to provide necessary pain control (e.g., epidural)
Theatre team - in case of failure to progress and an emergency cesarean section will be required.
Preparation

No specific preparation is required for face or brow presentation. However, it is essential to discuss the labor options with the mother and birthing partner and inform members of the neonatal, anesthetic, and theatre co-ordinating teams.

Technique or Treatment

Mechanism of Labor in Face Presentation

During contractions, the pressure exerted by the fundus of the uterus on the fetus and pressure of amniotic fluid initiate descent. During this descent, the fetal neck extends instead of flexing. The internal rotation determines the outcome of delivery, if the fetal chin rotates posteriorly, vaginal delivery would not be possible, and cesarean section is permitted. The approach towards mentum-posterior delivery should be individualized, as the cases are rare. Expectant management is acceptable in multiparous women with small fetuses, as a spontaneous mentum-anterior rotation can occur. However, there should be a low threshold for cesarean section in primigravida women or women with large fetuses.

When the fetal chin is rotated towards maternal symphysis pubis as described as mentum-anterior; in these cases further descend through the vaginal canal continues with approximately 73% cases deliver spontaneously. [9] Fetal mentum presses on the maternal symphysis pubis, and the head is delivered by flexion. The occiput is pointing towards the maternal back, and external rotation happens. Shoulders are delivered in the same manner as in vertex delivery.

Mechanism of Labor in Brow Presentation

As this presentation is considered unstable, it is usually converted into a face or an occiput presentation. Due to the cephalic diameter being wider than the maternal pelvis, the fetal head cannot engage; thus, brow delivery cannot take place. Unless the fetus is small or the pelvis is very wide, the prognosis for vaginal delivery is poor. With persistent brow presentation, a cesarean section is required for safe delivery.

Complications

As the cesarean section is becoming a more accessible mode of delivery in malpresentations, the incidence of maternal and fetal morbidity and mortality during face presentation has dropped significantly. [10]

However, there are still some complications associated with the nature of labor in face presentation. Due to the fetal head position, it is more challenging for the head to engage in the birth canal and descend, resulting in prolonged labor.

Prolonged labor itself can provoke foetal distress and arrhythmias. If the labor arrests or signs of fetal distress appear on CTG, the recommended next step in management is an emergency cesarean section, which in itself carries a myriad of operative and post-operative complications.

Finally, due to the nature of the fetal position and prolonged duration of labor in face presentation, neonates develop significant edema of the skull and face. Swelling of the fetal airway may also be present, resulting in respiratory distress after birth and possible intubation.

Clinical Significance

During vertex presentation, the fetal head flexes, bringing the chin to the chest, forming the smallest possible fetal head diameter, measuring approximately 9.5cm. With face and brow presentation, the neck hyperextends, resulting in greater cephalic diameters. As a result, the fetal head will engage later, and labor will progress more slowly. Failure to progress in labor is also more common in both presentations compared to vertex presentation.

Furthermore, when the fetal chin is in a posterior position, this prevents further flexion of the fetal neck, as browns are pressing on the symphysis pubis. As a result, descend through the birth canal is impossible. Such presentation is considered undeliverable vaginally and requires an emergency cesarean section.

Manual attempts to change face presentation to vertex, manual or forceps rotation to mentum anterior are considered dangerous and are discouraged.

Enhancing Healthcare Team Outcomes

A multidisciplinary team of healthcare experts supports the woman and her child during labor and the perinatal period. For a face or brow presentation to be appropriately diagnosed, an experienced midwife and obstetrician must be involved in the vaginal examination and labor monitoring. As fetal anomalies, such as anencephaly or goiter, can contribute to face presentation, sonographers experienced in antenatal scanning should also be involved in the care. It is advised to inform the anesthetic and neonatal teams in advance of the possible need for emergency cesarean section and resuscitation of the neonate. [11] [12]

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Disclosure: Julija Makajeva declares no relevant financial relationships with ineligible companies.

Disclosure: Mohsina Ashraf declares no relevant financial relationships with ineligible companies.

This book is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ), which permits others to distribute the work, provided that the article is not altered or used commercially. You are not required to obtain permission to distribute this article, provided that you credit the author and journal.

Cite this Page Makajeva J, Ashraf M. Delivery, Face and Brow Presentation. [Updated 2023 Jan 9]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-.

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Fetal Positions for Labor and Birth

Knowing your baby's position can you help ease pain and speed up labor

In the last weeks of pregnancy , determining your baby's position can help you manage pain and discomfort. Knowing your baby's position during early labor can help you adjust your own position during labor and possibly even speed up the process.

Right or Left Occiput Anterior

Illustration by JR Bee, Verywell

Looking at where the baby's head is in the birth canal helps determine the fetal position.The front of a baby's head is referred to as the anterior portion and the back is the posterior portion. There are two different positions called occiput anterior (OA) positions that may occur.

The left occiput anterior (LOA) position is the most common in labor. In this position, the baby's head is slightly off-center in the pelvis with the back of the head toward the mother's left thigh.

The right occiput anterior (ROA) presentation is also common in labor. In this position, the back of the baby is slightly off-center in the pelvis with the back of the head toward the mother's right thigh.

In general, OA positions do not lead to problems or additional pain during labor or birth.

Right or Left Occiput Transverse

Illustration by JR Bee, Verywell

When facing out toward the mother's right thigh, the baby is said to be left occiput transverse (LOT). This position is halfway between a posterior and anterior position. If the baby was previously in a posterior position (in either direction), the LOT position indicates positive movement toward an anterior position.

When the baby is facing outward toward the mother's left thigh, the baby is said to be right occiput transverse (ROT). Like the previous presentation, ROT is halfway between a posterior and anterior position. If the baby was previously in a posterior position, ROT is a sign the baby is making a positive move toward an anterior position.

When a baby is in the left occiput transverse position (LOT) or right occiput transverse (ROT) position during labor, it may lead to more pain and a slower progression.

Tips to Reduce Discomfort

There are several labor positions a mother can try to alleviate pain and encourage the baby to continue rotating toward an anterior position, including:

Pelvic tilts
Standing and swaying

A doula , labor nurse, midwife , or doctor may have other suggestions for positions.

Right or Left Occiput Posterior

When facing forward, the baby is in the occiput posterior position. If the baby is facing forward and slightly to the left (looking toward the mother's right thigh) it is in the left occiput posterior (LOP) position. This presentation can lead to more back pain (sometimes referred to as " back labor ") and slow progression of labor.

In the right occiput posterior position (ROP), the baby is facing forward and slightly to the right (looking toward the mother's left thigh). This presentation may slow labor and cause more pain.

To help prevent or decrease pain during labor and encourage the baby to move into a better position for delivery, mothers can try a variety of positions, including:

Hands and knees
Pelvic rocking

Mothers may try other comfort measures, including:

Bathtub or shower (water)
Counter pressure
Movement (swaying, dancing, sitting on a birth ball )
Rice socks (heat packs)

How a Doctor Determines Baby's Position

Leopold's maneuvers are a series of hands-on examinations your doctor or midwife will use to help determine your baby's position. During the third trimester , the assessment will be done at most of your prenatal visits. Knowing the baby's position before labor begins can help you prepare for labor and delivery.

Once labor begins, a nurse, doctor, or midwife will be able to get a more accurate sense of your baby's position by performing a vaginal exam. When your cervix is dilated enough, the practitioner will insert their fingers into the vagina and feel for the suture lines of the baby's skull as it moves down in the birth canal. It's important to ensure the baby is head down and moving in the right direction.

Labor and delivery may be more complicated if the baby is not in a head-down position, such as in the case of a breech presentation.

How You Can Determine Baby's Position

While exams by health practitioners are an important part of your care, from the prenatal period through labor and delivery, often the best person to assess a baby's position in the pelvis is you. Mothers should pay close attention to how the baby moves and where different movements are felt.

A technique called belly mapping can help mothers ask questions of themselves to assess their baby's movement and get a sense of the position they are in as labor approaches.

For example, the position of your baby's legs can be determined by asking questions about the location and strength of the kicking you feel. The spots where you feel the strongest kicks are most likely where your baby's feet are.

Other landmarks you can feel for include a large, flat plane, which is most likely your baby's back. Sometimes you can feel the baby arching his or her back.

At the top or bottom of the flat plane, you may feel either a hard, round shape (most likely your baby's head) or a soft curve (most likely to be your baby's bottom).

Guittier M, Othenin-Girard V, de Gasquet B, Irion O, Boulvain M. Maternal positioning to correct occiput posterior fetal position during the first stage of labour: a randomised controlled trial . BJOG: An International Journal of Obstetrics & Gynaecology . 2016;123(13):2199-2207. doi:10.1111/1471-0528.13855

Gizzo S, Di Gangi S, Noventa M, Bacile V, Zambon A, Nardelli G. Women’s Choice of Positions during Labour: Return to the Past or a Modern Way to Give Birth? A Cohort Study in Italy . Biomed Res Int . 2014;2014:1-7. doi:10.1155/2014/638093

Ahmad A, Webb S, Early B, Sitch A, Khan K, MacArthur C. Association between fetal position at onset of labor and mode of delivery: a prospective cohort study . Ultrasound in Obstetrics & Gynecology . 2014;43(2):176-182. doi:10.1002/uog.13189

Nishikawa M, Sakakibara H. Effect of nursing intervention program using abdominal palpation of Leopold’s maneuvers on maternal-fetal attachment . Reprod Health . 2013;10(1). doi:10.1186/1742-4755-10-12

Choi S, Park Y, Lee D, Ko H, Park I, Shin J. Sonographic assessment of fetal occiput position during labor for the prediction of labor dystocia and perinatal outcomes . The Journal of Maternal-Fetal & Neonatal Medicine . 2016;29(24):3988-3992. doi:10.3109/14767058.2016.1152250

Bamberg C, Deprest J, Sindhwani N et al. Evaluating fetal head dimension changes during labor using open magnetic resonance imaging . J Perinat Med . 2017;45(3). doi:10.1515/jpm-2016-0005

Gabbe S, Niebyl J, Simpson J et al. Obstetrics . Philadelphia, Pa.: Elsevier; 2012.

By Robin Elise Weiss, PhD, MPH Robin Elise Weiss, PhD, MPH is a professor, author, childbirth and postpartum educator, certified doula, and lactation counselor.

Fetal Presentation: Baby’s First Pose

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Occiput Anterior

Occiput posterior, transverse position, complete breech, frank breech, changing fetal presentation, baby positions.

The position in which your baby develops is called the “fetal presentation.” During most of your pregnancy, the baby will be curled up in a ball – that’s why we call it the “fetal position.” The baby might flip around over the course of development, which is why you can sometimes feel a foot poking into your side or an elbow prodding your bellybutton. As you get closer to delivery, the baby will change positions and move lower in your uterus in preparation. Over the last part of your pregnancy, your doctor or medical care provider will monitor the baby’s position to keep an eye out for any potential problems.

In the occiput anterior position, the baby is pointed headfirst toward the birth canal and is facing down – toward your back. This is the easiest possible position for delivery because it allows the crown of the baby’s head to pass through first, followed by the shoulders and the rest of the body. The crown of the head is the narrowest part, so it can lead the way for the rest of the head.

The baby’s head will move slowly downward as you get closer to delivery until it “engages” with your pelvis. At that point, the baby’s head will fit snugly and won’t be able to wobble around. That’s exactly where you want to be just before labor. The occiput anterior position causes the least stress on your little one and the easiest labor for you.

In the occiput posterior position, the baby is pointed headfirst toward the birth canal but is facing upward, toward your stomach. This can trap the baby’s head under your pubic bone, making it harder to get out through the birth canal. In most cases, a baby in the occiput posterior position will either turn around naturally during the course of labor or your doctor or midwife may help it along manually or with forceps.

In a transverse position, the baby is sideways across the birth canal rather than head- or feet-first. It’s rare for a baby to stay in this position all the way up to delivery, but your doctor may attempt to gently push on your abdomen until the baby is in a more favorable fetal presentation. If you go into labor while the baby is in a transverse position, your medical care provider will likely recommend a c-section to avoid stressing or injuring the baby.

Breech Presentation

If the baby’s legs or buttocks are leading the way instead of the head, it’s called a breech presentation. It’s much harder to deliver in this position – the baby’s limbs are unlikely to line up all in the right direction and the birth canal likely won’t be stretched enough to allow the head to pass. Breech presentation used to be extremely dangerous for mothers and children both, and it’s still not easy, but medical intervention can help.

Sometimes, the baby will turn around and you’ll be able to deliver vaginally. Most healthcare providers, however, recommend a cesarean section for all breech babies because of the risks of serious injury to both mother and child in a breech vaginal delivery.

A complete breech position refers to the baby being upside down for delivery – feet first and head up. The baby’s legs are folded up and the feet are near the buttocks.

In a frank breech position, the baby’s legs are extended and the baby’s buttocks are closest to the birth canal. This is the most common breech presentation .

By late in your pregnancy, your baby can already move around – you’re probably feeling those kicks! Unfortunately, your little one doesn’t necessarily know how to aim for the birth canal. If the baby isn’t in the occiput anterior position by about 32 weeks, your doctor or midwife will typically recommend trying adjust the fetal presentation. They’ll use monitors to keep an eye on the baby and watch for signs of stress as they push and lift on your belly to coax your little one into the right spot. Your doctor may also advise you to try certain exercises at home to encourage the baby to move into the proper position. For example, getting on your hands and knees for a few minutes every day can help bring the baby around. You can also put cushions on your chairs to make sure your hips are always elevated, which can help move things into the right place. It’s important to start working on the proper fetal position early, as it becomes much harder to adjust after about 37 weeks when there’s less room to move around.

In many cases, the baby will eventually line up properly before delivery. Sometimes, however, the baby is still in the wrong spot by the time you go into labor. Your doctor or midwife may be able to move the baby during labor using forceps or ventouse . If that’s not possible, it’s generally safer for you and the baby if you deliver by c-section.

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Fetal Presentation, Position, and Lie (Including Breech Presentation)

Variations in Fetal Position and Presentation |

During pregnancy, the fetus can be positioned in many different ways inside the mother's uterus. The fetus may be head up or down or facing the mother's back or front. At first, the fetus can move around easily or shift position as the mother moves. Toward the end of the pregnancy the fetus is larger, has less room to move, and stays in one position. How the fetus is positioned has an important effect on delivery and, for certain positions, a cesarean delivery is necessary. There are medical terms that describe precisely how the fetus is positioned, and identifying the fetal position helps doctors to anticipate potential difficulties during labor and delivery.

Presentation refers to the part of the fetus’s body that leads the way out through the birth canal (called the presenting part). Usually, the head leads the way, but sometimes the buttocks (breech presentation), shoulder, or face leads the way.

Position refers to whether the fetus is facing backward (occiput anterior) or forward (occiput posterior). The occiput is a bone at the back of the baby's head. Therefore, facing backward is called occiput anterior (facing the mother’s back and facing down when the mother lies on her back). Facing forward is called occiput posterior (facing toward the mother's pubic bone and facing up when the mother lies on her back).

Lie refers to the angle of the fetus in relation to the mother and the uterus. Up-and-down (with the baby's spine parallel to mother's spine, called longitudinal) is normal, but sometimes the lie is sideways (transverse) or at an angle (oblique).

For these aspects of fetal positioning, the combination that is the most common, safest, and easiest for the mother to deliver is the following:

Head first (called vertex or cephalic presentation)

Facing backward (occiput anterior position)

Spine parallel to mother's spine (longitudinal lie)

Neck bent forward with chin tucked

Arms folded across the chest

If the fetus is in a different position, lie, or presentation, labor may be more difficult, and a normal vaginal delivery may not be possible.

Variations in fetal presentation, position, or lie may occur when

The fetus is too large for the mother's pelvis (fetopelvic disproportion).

The uterus is abnormally shaped or contains growths such as fibroids .

The fetus has a birth defect .

There is more than one fetus (multiple gestation).

Position and Presentation of the Fetus

Variations in fetal position and presentation.

Some variations in position and presentation that make delivery difficult occur frequently.

Occiput posterior position

In occiput posterior position (sometimes called sunny-side up), the fetus is head first (vertex presentation) but is facing forward (toward the mother's pubic bone—that is, facing up when the mother lies on her back). This is a very common position that is not abnormal, but it makes delivery more difficult than when the fetus is in the occiput anterior position (facing toward the mother's spine—that is facing down when the mother lies on her back).

When a fetus faces up, the neck is often straightened rather than bent,which requires more room for the head to pass through the birth canal. Delivery assisted by a vacuum device or forceps or cesarean delivery may be necessary.

Breech presentation

In breech presentation, the baby's buttocks or sometimes the feet are positioned to deliver first (before the head).

When delivered vaginally, babies that present buttocks first are more at risk of injury or even death than those that present head first.

The reason for the risks to babies in breech presentation is that the baby's hips and buttocks are not as wide as the head. Therefore, when the hips and buttocks pass through the cervix first, the passageway may not be wide enough for the head to pass through. In addition, when the head follows the buttocks, the neck may be bent slightly backwards. The neck being bent backward increases the width required for delivery as compared to when the head is angled forward with the chin tucked, which is the position that is easiest for delivery. Thus, the baby’s body may be delivered and then the head may get caught and not be able to pass through the birth canal. When the baby’s head is caught, this puts pressure on the umbilical cord in the birth canal, so that very little oxygen can reach the baby. Brain damage due to lack of oxygen is more common among breech babies than among those presenting head first.

In a first delivery, these problems may occur more frequently because a woman’s tissues have not been stretched by previous deliveries. Because of risk of injury or even death to the baby, cesarean delivery is preferred when the fetus is in breech presentation, unless the doctor is very experienced with and skilled at delivering breech babies or there is not an adequate facility or equipment to safely perform a cesarean delivery.

Breech presentation is more likely to occur in the following circumstances:

Labor starts too soon (preterm labor).

The uterus is abnormally shaped or contains abnormal growths such as fibroids .

Abnormal Fetal lie, Malpresentation and Malposition

Original Author(s): Anna Mcclune Last updated: 1st December 2018 Revisions: 12

1 Definitions
2 Risk Factors
3.2 Presentation
3.3 Position
4 Investigations
5.1 Abnormal Fetal Lie
5.2 Malpresentation
5.3 Malposition

The lie, presentation and position of a fetus are important during labour and delivery.

In this article, we will look at the risk factors, examination and management of abnormal fetal lie, malpresentation and malposition.

Definitions

Longitudinal, transverse or oblique
Cephalic vertex presentation is the most common and is considered the safest
Other presentations include breech, shoulder, face and brow
Usually the fetal head engages in the occipito-anterior position (the fetal occiput facing anteriorly) – this is ideal for birth
Other positions include occipito-posterior and occipito-transverse.

Note: Breech presentation is the most common malpresentation, and is covered in detail here .

Fig 1 – The two most common fetal presentations: cephalic and breech.

Risk Factors

The risk factors for abnormal fetal lie, malpresentation and malposition include:

Multiple pregnancy
Uterine abnormalities (e.g fibroids, partial septate uterus)
Fetal abnormalities
Placenta praevia
Primiparity

Identifying Fetal Lie, Presentation and Position

The fetal lie and presentation can usually be identified via abdominal examination. The fetal position is ascertained by vaginal examination.

For more information on the obstetric examination, see here .

Face the patient’s head
Place your hands on either side of the uterus and gently apply pressure; one side will feel fuller and firmer – this is the back, and fetal limbs may feel ‘knobbly’ on the opposite side

Presentation

Palpate the lower uterus (above the symphysis pubis) with the fingers of both hands; the head feels hard and round (cephalic) and the bottom feels soft and triangular (breech)
You may be able to gently push the fetal head from side to side

The fetal lie and presentation may not be possible to identify if the mother has a high BMI, if she has not emptied her bladder, if the fetus is small or if there is polyhydramnios .

During labour, vaginal examination is used to assess the position of the fetal head (in a cephalic vertex presentation). The landmarks of the fetal head, including the anterior and posterior fontanelles, indicate the position.

Fig 2 – Assessing fetal lie and presentation.

Investigations

Any suspected abnormal fetal lie or malpresentation should be confirmed by an ultrasound scan . This could also demonstrate predisposing uterine or fetal abnormalities.

Abnormal Fetal Lie

If the fetal lie is abnormal, an external cephalic version (ECV) can be attempted – ideally between 36 and 38 weeks gestation.

ECV is the manipulation of the fetus to a cephalic presentation through the maternal abdomen.

It has an approximate success rate of 50% in primiparous women and 60% in multiparous women. Only 8% of breech presentations will spontaneously revert to cephalic in primiparous women over 36 weeks gestation.

Complications of ECV are rare but include fetal distress , premature rupture of membranes, antepartum haemorrhage (APH) and placental abruption. The risk of an emergency caesarean section (C-section) within 24 hours is around 1 in 200.

ECV is contraindicated in women with a recent APH, ruptured membranes, uterine abnormalities or a previous C-section .

Fig 3 – External cephalic version.

Malpresentation

The management of malpresentation is dependent on the presentation.

Breech – attempt ECV before labour, vaginal breech delivery or C-section
Brow – a C-section is necessary
If the chin is anterior (mento-anterior) a normal labour is possible; however, it is likely to be prolonged and there is an increased risk of a C-section being required
If the chin is posterior (mento-posterior) then a C-section is necessary
Shoulder – a C-section is necessary

Malposition

90% of malpositions spontaneously rotate to occipito-anterior as labour progresses. If the fetal head does not rotate, rotation and operative vaginal delivery can be attempted. Alternatively a C-section can be performed.

Usually the fetal head engages in the occipito-anterior position (the fetal occiput facing anteriorly) - this is ideal for birth

If the fetal lie is abnormal, an external cephalic version (ECV) can be attempted - ideally between 36 and 38 weeks gestation.

Breech - attempt ECV before labour, vaginal breech delivery or C-section

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Abnormal Fetal Lie and Presentation

Introduction.

The normal process of parturition relies in part, on the physical relationships between the fetus and maternal bony outlet. In addition, fetal posture, placental and cord locations, as well as maternal soft tissues also are factors in the efficiency and safety of the birth process.

This chapter discusses how to define, diagnose, and manage the clinical impact of abnormalities of fetal lie and malpresentation. The most common clinical correlation of the abnormal fetal lies and presentations is the breech-presenting fetus.

DEFINITIONS

In describing fetopelvic relationships, the clinician should carefully adhere to standard obstetrical nomenclature. Fetal lie refers to the relationship between the long axis of the fetus with respect to the long axis of the mother. The possibilities include a longitudinal lie, a transverse lie, and, on occasion, an oblique lie. Fetal presentation is a reference to the part of the fetus that is overlying the maternal pelvic inlet.

The most common relationship between fetus and mother is the longitudinal lie, cephalic presentation. A breech fetus also is a longitudinal lie, with the fetal buttocks as the presenting part. Breech fetuses also are referred to as malpresentations because of the many problems associated with them. Fetuses that are in a transverse lie may present the fetal back (or shoulders, as in the acromial presentation), small parts (arms and legs), or the umbilical cord (as in a funic presentation) to the pelvic inlet. In an oblique lie, the fetal long axis is at an angle to the bony inlet, and no palpable fetal part generally is presenting. This lie usually is transitory and occurs during fetal conversion between other lies.

The most dependent portion of the presenting part is known as the point of direction. The occiput is the point of direction of a well-flexed fetus in cephalic presentation. The fetal position refers to the location of the point of direction with reference to the four quadrants of the maternal outlet as viewed by the examiner. Thus, position may be right or left as well as anterior or posterior.

Fetal attitude refers to the posture of a fetus during labor. Mammalian fetuses have a tendency to assume a fully flexed posture during development and during parturition. Flexion of the fetal head on the chest allows for the delivery of the head by its smallest bony diameter. A loss of this flexed posture presents a progressively larger fetal head to the bony pelvis for labor and delivery (Fig. 1). The fetal arms and legs also tend to assume a fully flexed posture. The longitudinal posture of the fetus likewise is flexed under normal circumstances.

The mechanism of labor and delivery, as well as its inherent safety and efficacy, is determined by the specifics of the fetopelvic relationship at the onset of labor. Further correlations with fetopelvic relationships are important before birth.

The relative incidence of differing fetopelvic relations varies with diagnostic and clinical approaches to care. Among longitudinal lies, about 1 in 25 fetuses are not cephalic but breech at the onset of labor. 1 Of the differing lies a fetus may assume, about 1 in 100 is transverse or oblique, also referred to as nonaxial.

As pregnancy proceeds to term, most fetuses assume a longitudinal lie with relationship with the maternal outlet. Conversely, when labor and delivery are considered to be remote from term, the proportion of fetuses in abnormal and suboptimal locations increases ( Table 1 ).

Table 1. Breech presentation by gestational age

Transverse and oblique lies also are seen with greater frequency earlier in gestation. A fetus in a transverse lie may present the shoulder or acromion as a point of reference to the examiner. As term approaches, spontaneous conversion to a longitudinal lie is the norm. As seen with breech presentation, there is a rapid decrease in nonaxial lie during the third trimester. With the comprehensive application of ultrasound in the antepartum period, discovery of a transverse or oblique lie has increased. However, nonaxial fetal lies usually are transitory.

Abnormal fetal lie frequently is seen in multifetal gestation, particularly with the second twin. A transverse lie may be encountered with large discrepancies in fetopelvic parameters, such as exist with extreme prematurity and macrosomia. This tendency is greater in women of grand parity, in whom relaxation of the abdominal and uterine musculature is cited as the predisposing factor. Distortion of the uterine cavity shape, such as that seen with leiomyomas, prior uterine surgery, or developmental anomalies (Mullerian fusion defects), coexists with both abnormalities in fetal lie and malpresentation. Placental location also may play a contributing role. Fundal and cornual implantation are seen more frequently in breech presentation. Placenta previa is a well-described concomitant in both transverse lie and breech presentation. 2

Congenital anomalies of the fetus also are seen in association with abnormalities in either presentation or lie. 3 Whether a cause (as in fitting the uterine cavity optimally) or effect (the fetus with a neuromuscular condition that prevents the normal turning mechanism), the finding of an abnormal lie or malpresentation requires a thorough search for fetal maldevelopment. Abnormalities seen include chromosomal (autosomal trisomy) and structural abnormalities (hydrocephalus), as well as syndromes of multiple effects (fetal alcohol syndrome) ( Table 2 ).

Table 2. Anomalies frequently diagnosed in breech fetuses

Congenital anomalies of major structures are seen in 3–5% of all births. The incidence in breech delivery is three times greater when controlled for gestational age. Among premature breech infants, the incidence is even greater, as it is for all fetuses born prematurely.

Prematurity is a crucial factor in the incidence as well as the clinical implications of abnormal fetal lie and malpresentation. Fetal size and shape undergo dramatic change during the second and third trimester (Fig. 2, Table 3 ).

Table 3. Head circumference: abdominal circumference ratio by gestational age

SD, standard deviations (Adapted from Campbell S, Metreweli C [eds]: Practical Abdominal Ultrasound. Chicago, Year Book Medical Publishers, 1978)

Because the fetus has a relatively larger head than body during most of the late second and early third trimester, the fetus tends to spend much of its time in breech presentation or in a nonaxial lie as it rotates back and forth between cephalic and breech presentations. The relatively large volume of amniotic fluid present facilitates these dynamics.

Breech presentation is more common at earlier gestation and therefore is seen more frequently among low-birth weight infants 4 ( Table 4 ). Breech infants are more likely to be small for gestational age regardless of their gestation at delivery.

Table 4. Incidence of breech presentation by birth weight

The small size of the premature fetus is further compromised by the specific malpresentations that occur. With less neurologic and muscular control, deflexed or even extended varieties of fetal presentations are seen. Most common are the “incomplete” types of breech presentation, such as footling breech presentations (Fig. 3, Tables 5 and 6 ). Deflexion of the fetal head, more commonly seen in preterm fetuses, results in the potential for further compromise at delivery.

Table 5. Varieties of breech presentation

Table 6. Type of breech presentation in labor by gestational age

(Adapted from Gimovsky M, Petrie RH: Breech presentation. In Evans M, Fletcher J, Dixler A et al [eds]: Fetal Diagnosis and Therapy, pp 276–295. Philadelphia, JB Lippincott, 1989.)

Thus, the problems associated with abnormal lie and malpresentation are most frequent and of greatest consequence in preterm labor and delivery. At term, similar, though usually less dramatic, consequences may be seen with fetuses who are in abnormal positions.

PERINATAL MORBIDITY AND MORTALITY

Perinatal morbidity and mortality is threefold higher in breech presentation than cephalic presentation. Much of this excessive compromise is caused by factors that are not directly preventable. According to Kaupilla, 5 64% of deaths among term breech infants resulted from congenital malformations or infection. In a different population, Todd and Steer 6 found that 23 of 34 term breech deaths among 1006 term infants were not related to complications of breech delivery but were associated with anomalies, infection, and isoimmunization.

As noted earlier, preterm and small-for-gestational age infants commonly are associated with breech labor and delivery. As for term breech infants, experience indicates that most of the adverse outcomes seen are unrelated to breech delivery. Thus, for all breech fetuses, about one third of the excessive perinatal loss falls to birth trauma and asphyxia.

COMPLICATIONS AND COUNSELING

The complications associated with abnormal fetal lie and malpresentations include both maternal and fetal. As noted earlier, prematurity and malpresentation are strongly related. Circumstances in which premature birth may occur also include maternal complications such as pregnancy-induced hypertension and medical complications (cardiovascular, neoplastic), as well as obstetric problems such as premature rupture of membranes and chorioamnionitis. The circumstances dictating delivery may further compromise the preterm fetus.

The obstetric complications for the fetus include a diverse group of misadventures. Prolapse of the umbilical cord, intrauterine infection, maldevelopment as a result of oligohydramnios, asphyxia, and birth trauma all are concerns.

Birth trauma, particularly to the head and cervical spine, is a significant risk to both term and preterm infants who present as breech presentation or in a nonaxial lie. 7 , 8 , 9 Unlike the cephalic fetus in whom hours of adaptation to the maternal bony pelvis (molding) may occur, the after-coming head of the breech fetus must descend and deliver rapidly and without significant change in shape. Therefore, small alterations in the dimensions or shape of the maternal bony pelvis or the attitude of the fetal head may have grave consequences. As discussed earlier, this process is of greater risk to the preterm infant because of the relative size of the fetal head and body. Trauma to the head is not eliminated by cesarean section; both intracranial and cervical spine trauma may result from entrapment in either the uterine or abdominal incisions. 10

The fetus in the transverse lie, regardless of gestational age, generally requires cesarean delivery. At cesarean section, delivery may be aided by converting the fetus to a longitudinal lie for the delivery after entering the abdomen. This conversion may allow for the use of a transverse incision into the uterus instead of the more morbid vertical incision.

External cephalic version (ECV) should be considered in a nonlaboring patient. When the diagnosis is first made at term, spontaneous conversion to a longitudinal lie is less common than for its breech counterpart. This results from the higher incidence of structural causes for the transverse lie.

When abnormal presentation or lie occurs in a twin gestation, management includes a greater range of options. The conversion of a backup transverse second twin, either by internal or external version at the time of delivery, is an option for the experienced clinician. When the back is down at the time of delivery, the prudent course for the delivery of a fetus in transverse lie is by cesarean section. Strong consideration should be given to the incisions at delivery in this circumstance, with a vertical uterine incision being used liberally.

When a fetus in a transverse lie is diagnosed remote from delivery, as occurs at time of ultrasound, the physician is faced with an additional dilemma. Spontaneous rupture of membranes may result in cord prolapse or compromise with the risk of fetal asphyxia. Delivery at the time of antepartum ultrasound before term may result in jeopardy because of prematurity. External version, as a correction, may be attempted as long as ultrasound excludes placenta previa and documents an appropriate amount of amniotic fluid. Experience has demonstrated some success, although in general, the use of ECV is more likely to be successful for a breech-presenting fetus.

The patient should be carefully counseled about the problem and its inherent risks. Hospitalization and observation may be considered. However, the cost–benefit ratio in this era of managed care makes prolonged hospitalization unlikely under most circumstances. I recommend twice-weekly fetal surveillance to assess for cord compromise. The patient should be warned about the signs and symptoms of preterm labor and encouraged to present to labor and delivery should these conditions arise. Under certain circumstances, home uterine activity monitoring may provide a useful adjunct.

The antepartum diagnosis of persistent breech presentation is accompanied by similar concerns. In addition, careful evaluation for fetal anomalies is warranted. A targeted ultrasound by an experienced ultrasonographer is useful to diagnosis structural fetal defects and to ascertain appropriate fetal growth. Prenatal diagnosis by maternal screening or amniocentesis may be indicated.

When premature rupture of membranes occurs, consideration of a timely delivery should ensue. Depending on gestational age, amniotic fluid volume, and cervical evaluation, a limited course of tocolysis, antibiotics, and steroid administration may be indicated. When a fetus with an abnormal lie or malpresentation presents under these circumstances, hospital care is best managed within the confines of labor and delivery, where fetal surveillance can be maintained on a continual basis. This is indicated primarily because of the risk of cord prolapse or compromise. With severe oligohydramnios, the high incidence of intrauterine infection adds measurably to the risks of maintaining the fetus in utero, and an expedited delivery is warranted routinely.

INTRAPARTUM COMPLICATIONS AND COUNSELING

As previously discussed, the new intrapartum diagnosis of a transverse lie generally results in an expedited cesarean delivery. When a transverse lie is associated with prolapse of the umbilical cord, a true obstetric emergency may arise. Pelvic examination, with relief of pressure against the umbilical cord, should be performed and parenteral tocolysis administered if contraindications are not present. Changes in maternal positioning, particularly the lateral supine position, usually are well tolerated by both patient and practitioner.

Transport to a delivery room equipped for cesarean delivery should be accomplished promptly. When setup is complete, abdominal delivery is performed. A consideration for a limited attempt at version may play a role in this clinical scenario after anesthesia has been satisfactorily obtained.

Clinically more common is the diagnosis of a breech presentation at or near term. Prenatal visits in the third trimester should include Leopold maneuvers and should frequently include ultrasound as an adjunct. Also, they should always include the consideration that malpresentation may exist. The diagnosis of this situation before the onset of labor should be the goal because this allows for a larger and safer range of options. 11

After a diagnosis is confirmed, the patient deserves as thorough an explanation as is called for by the specific situation. She likely has heard, at least peripherally, that a breech baby means a mandatory cesarean section.

Whereas there is some truth in this simple association, I strongly believe that as the patient's advocate, physicians undertake the responsibility to provide a fuller discussion. Most breech fetuses at term are not a complex problem. Most do not have congenital anomalies or other adverse obstetric problems. Their potential problem centers on the risks of asphyxia and trauma during labor and delivery.

Clearly, this group of risks, however clinicians clinically work to minimize them, are best avoided if possible. Therefore, the diagnosis of breech presentation before labor allows the patient to undergo ECV and hopefully delivery as a cephalic fetus (Fig. 4). ECV is a time-honored approach to correct a “malpresentation.” It was used in the past as soon as the diagnosis of a breech fetus was made. This led to many second-trimester and early third-trimester procedures. Given the size of the fetus and the quantity of amniotic fluid present, it is not surprising that the failure rate was high. Because most of these fetuses would have spontaneously converted to cephalic presentations at the time of labor, using ECV resulted in many unnecessary procedures 12 ( Table 7 ).

Table 7. Spontaneous conversion of breech to cephalic presentation

(Adapted from Westgren M, Edvall H, Nordstrom L et al: Spontaneous cephalic version of breech presentation in the last trimester. Br J Obstet Gynaecol 92:19, 1985)

In fact, the earlier practitioners of the 20th century used sufficient force to avoid the need for a cesarean section under these circumstances that general anesthesia was used, as well as regional anesthesia and analgesics. Unfortunately, the great forces were associated with serious trauma to the placenta and uterus. Spontaneous rupture of both the uterus and the membranes, placental abruption, and fetal isoimmunization also were seen and resulted in the abandonment of this approach.

ECV performed on a fetus at term and in the absence of maternal anesthesia or analgesia made a return to practice in the 1970s. 13 , 14 By performing ECV at term, spontaneous conversion reduced the population at need for a cesarean section for breech presentation. 12 By performing ECV at term and within the labor and delivery area, means were available for immediate cesarean delivery if a problem ensued. Several groups have demonstrated a high degree of success with ECV in the late third trimester. 15 , 16 , 17

Even under these circumstances and safeguards, ECV is not entirely risk free. Although usually of no clinical consequence, fetal bradycardia is common during the procedure. Antepartum bleeding, isoimmunization, and fetal death (acute and remote) have been described. 18 Furthermore, conversion may cause deflexion of the fetal head or result in a funic presentation, either of which might require a cesarean delivery in and of itself. 19 , 20

If ECV fails or if the patient finds it unacceptable, at least two further choices remain. The first is delivery by cesarean section. If the patient is a candidate, the second is a selective trial of labor.

Once the diagnosis of breech presentation has been confirmed and attempts at ECV have failed, both patient and physician require a heightened effort at communication to ensure that a plan of care is established that is mutually acceptable. Potential risks for the breech fetus approaching term include umbilical cord prolapse, prolapse of the fetus before complete cervical dilation is achieved, and a rapidly progressive labor, with delivery imminent on arrival or even en route to labor and delivery.

Prolapse of the umbilical cord is an unusual complication in a term fetus in the early stages of labor. Because a breech fetus presents a smaller and less complete covering to the pelvic inlet, this risk is greater for all breech fetuses in comparison with all cephalic fetuses. Among breech fetus, the less complete the flexion of the lower extremities—such as occurs in footling breech presentations—the greater the risk.

Other factors, however, play a role in mitigating or increasing this risk. The nonasphyxiated fetus generally possesses a turgid umbilical cord, coated in Wharton jelly. With normal blood flow, cord prolapse is unlikely, regardless of position. Prolapse of the cord also is decidedly more common in the second stage of labor, when maternal expulsive efforts result in expression of the uterine contents ( Table 8 ).

Table 8. External cephalic version late in pregnancy

The exception occurs when the cord is located as the most dependent fetal part at the onset of labor, as seen in funic presentations. Ultrasound examination, in conjunction with color Doppler scan, can help to locate the exact position of the umbilical cord and should be performed at the time of ECV.

Prolapse of the fetus before achieving full cervical dilation, particularly in a rapidly progressive labor, is another concern. The fetus most likely to experience adverse consequences from this complication has a low birth weight and usually is preterm. 21 The breech fetus that is incomplete in flexion (the single- and double-footling varieties) has a greater tendency to prolapse under this premature descent. Unfortunately, this group is disproportionately represented in fetuses delivering preterm. The most common breech fetuses, frank and complete presentations, comprise most breech fetuses at term. Their risk of cord prolapse, or body prolapse before second stage, is only marginally greater than their cephalic counterparts. Thus, the patient and physician confronted with a frank or complete breech presentation at term and after a failed attempt at ECV should be reassured that although these risks exist, their occurrence is rare, in the order of 1 to 3 per 1000. 22

What about the woman with extremely rapid labor, or the patient who resides at a great distance from the hospital? Delivery of a breech fetus requires an experienced clinician to ensure the maximum safety of both infant and mother. Serious consideration should be given to induction of labor at term, after fetal lung maturation is assured. Cervical ripening and induction of labor may be conducted in the same manner as for a cephalic fetus. By scheduling the delivery of a breech fetus, either by cesarean section or by induction, the proper resources, both personnel and equipment, can be assured. 23 , 24

If a cesarean section is chosen, appropriate arrangements can be made, as delineated earlier in reference to a scheduled induction of labor. Cesarean section before the onset of labor avoids the additional risks of both cord prolapse and body prolapse before complete dilation and is associated with a lessened risk of anesthesia for the parturient. 25

INTRAPARTUM MANAGEMENT

Cesarean delivery has been liberally used to decrease perinatal mortality and morbidity for the breech fetus. The potential to avoid birth trauma and asphyxia led to its application to a greater extent even in the early part of the 20th century, when the safety of cesarean delivery was in greater question. As its use increased, the perinatal mortality associated with a live, nonanomalous fetus at term dropped dramatically 26 (Fig. 5).

Wright, in 1959, 27 called for the exclusive use of cesarean delivery for breech fetuses. In this and earlier eras, prematurity, low birth weight, or congenital anomalies went untreated or undertreated, and so the only group of breech fetuses that had a chance for survival were those infants born of normal weight at term. With the avoidance of intrapartum asphyxia or birth trauma sustained during delivery, the outcome could be improved. Indeed, a great difference in outcome was attributed by some to the risks of labor and delivery 28 ( Table 9 ).

Table 9. Outcome of breech infants weighing more than 2500 g, 1973–1980

(Adapted from Weingold AB: The Management of Breech Presentation. In Iffy L, Charles C [eds]: Operative Perinatology, pp 357–553. New York, Macmillan, 1984)

Although the liberal use of cesarean delivery is indicated for breech fetuses, there is concern about whether its routine use is warranted. In a study by Green and coworkers, 29 the rate of cesarean delivery for breech increased from 22% to 94% on the same medical service over a 15-year interval. Despite this extensive application of cesarean delivery, the perinatal outcome, as measured by evidence of asphyxia, trauma, or intrapartum death, was unchanged ( Table 10 ).

Table 10. Outcome of breech presenting fetuses at term by method of delivery

Cesarean delivery increases maternal morbidity and mortality, albeit to a lesser extent than in the past. The relative risks and benefits to both mother and infant should be presented by the physician to the patient ( Table 11 ). The cost, both economic and psychological, of cesarean delivery also has been debated. In past eras, a greater dollar cost was associated with abdominal delivery. With shorter stays and improved approaches to cesarean delivery, the difference has narrowed.

Table 11. Perinatal and maternal morbidity associated with breech labor and delivery

Another approach is the selective use of a trial of labor. By identifying which breech fetuses and mothers have the greatest predictable risk, cesarean delivery can be used for the group likely to have the greatest gain. By avoiding cesarean delivery in the low-risk pairings, use of cesarean delivery can be minimized, with subsequent savings to the health system of limited resources.

Many authors realize the potential benefits of such an approach. 30 , 31 , 32 At a 4% incidence and at 4 million births a year, some 160,000 pregnancies are complicated by a breech-presenting fetus at term on an annual basis. At a rate of cesarean delivery of about 90%, this results in 144,000 procedures, almost one-fifth that of cesarean delivery. By selecting a low-risk group for a trial of labor, the overall use of cesarean delivery for this indication might be reduced to 50%, saving more than 60,000 major surgeries a year, or 8% of the total cesarean deliveries performed.

This savings would be moot if there were a corresponding increase in perinatal morbidity and mortality associated with this practice shift. The available data on selective trials of labor support such an approach and suggest that the additional fetal risk is minimal and justified by the reduction in maternal morbidity and mortality.

Some of the factors for consideration in determining the risks for an individual patient already have been mentioned. Given the size and shape of the low birth weight breech fetus, most authors agree that fetuses who are breech and require delivery between 1000 and 2000 g are best served by cesarean delivery. The group of preterm fetuses weighing less than 1000 g and in need of delivery require individual assessment. The trauma to be avoided at vaginal delivery may occur at cesarean delivery. The need for vertical uterine incisions, which may require extension into the fundus, makes breech extraction difficult. This is particularly true in the presence of ruptured membranes. Entrapment of the after-coming head is of particular concern in this weight group. As outlined earlier, the head–abdomen ratio and the incidence if “incomplete” types of breech fetuses are predisposing factors. Entrapment occurs at both cesarean delivery and vaginal deliveries with these low birth weight infants. Delivery “en caul” may mitigate against head entrapment at cesarean delivery or vaginal delivery after the delivery of the small fetus.

At the other extreme, the macrosomic breech fetus also is an indication for cesarean delivery. Even with a favorable head–abdomen ratio at term, dystocia may be encountered with the delivery of either the fetal abdomen or after-coming head.

When the fetal head is extended, there is increased concern for the safety of delivery by either route. 8 , 33 A careful evaluation by radiograph or ultrasound should be a part of the predelivery examination of a patient with a breech fetus, regardless of the route of delivery chosen. 34 Extension of the after-coming head, diagnosed as an angle of greater than 105 degrees between the mandible and the cervical spine, may compromise the cervical spinal cord during delivery (see Fig. 1). Extension is uncommon (less than 5%) and may result from fetal goiter, a nuchal cord, or abnormalities of the shape of the uterine cavity. Additionally, extension may be caused by, or may be a sign of, fetal neurologic compromise, with an inability of the fetus to adequately flex his head on his chest. Extension should result in delivery by cesarean delivery. Extra care should be taken at cesarean delivery to cause the fetal head to flex during delivery by applying force on the fetal head during delivery. This ameliorates the tendency to fetal extension that occurs with the breech extraction used by some in a cesarean delivery. 35

Prolapse of the umbilical cord is decidedly rare in the first stage of labor. However, with single- and double-footling breech fetuses, the risk increases greatly during the second stage. Therefore, some authors exclude these specific types of breech fetuses from consideration for a trial of labor.

For the more common frank and complete types of breech presentation, the risk of cord prolapse is the same or only marginally greater than for a cephalic fetus. It is within this group, who constitute most breech fetuses at term, that a selective trial of labor will have the greatest benefit 36 ( Table 12 ).

Table 12. Selection characteristics for a trial of labor in a breech presentation

Measurement of the bony pelvis is performed to exclude borderline pelvic diameters. I advocate the use of radiologic measurement of the maternal bony pelvis. Computed tomography scan reliably measures pelvic dimensions and the attitude of the fetal head. Magnetic resonance imaging also has been successfully used in this setting. 37 The outcome of term breech delivery may be facilitated by only allowing a trial in women with pelvic measurements shown to be associated with successful breech delivery. 38 Todd and Steer, 6 in reviewing more than 1000 breech deliveries at term, demonstrated a critical difference in perinatal outcome when the pelvic inlet measured greater than 12 cm at the transverse of the inlet, and greater than 11 cm for the AP diameter. Gimovsky and associates 38 expanded this to include a midpelvic diameter of greater than 10 cm ( Table 13 ). Several authors have demonstrated the efficacy of this measure. 39 The use of computed tomography scanning results in a limited exposure of the fetus to ionizing radiation. 40 An additional benefit is the reproducibility and ease with which pelvic measurements may be obtained.

Table 13. Results of X-ray pelvimetry in a group of women undergoing a successful trial of labor under protocol

Typically, three views are obtained (Fig. 6). Because most patients will have undergone a failed attempt at ECV, I obtain pelvimetry at that time for the patient selected for a trial of labor. Patients in whom we are unable to convert a breech presentation are unlikely to undergo spontaneous conversion. Alternatively, pelvimetry may be obtained on presentation in early labor.

MANAGEMENT OF LABOR AND DELIVERY

When a trial of labor is undertaken with a breech-presenting fetus, it is crucial for an expedited cesarean delivery to be continuously available. The usual indicators of fetal well-being, as well as the adequacy of the progression of labor, will give rise to the indication for cesarean delivery on occasion. The criteria clinically used in supervising the labor of a cephalic fetus should be applied to the selected term breech fetus. In my experience, as well as others, cervical ripening, oxytocin induction, and partographic analysis of labor are safe and efficacious. Augmentation, when indicated, should call for a thoughtful re-evaluation of all aspects of the situation. For example, is the fetal size less than 4000 g? Has descent occurred progressively during the second stage? Have adequate maternal expulsive efforts failed to effect “crowning?” Oxytocin augmentation should be used only after an internal pressure transducer indicates inadequate contractions. Cesarean delivery should be used liberally in all other circumstances.

Fetal surveillance during labor and delivery should be continuous. After spontaneous rupture of membranes, internal monitoring may be used. Fetal heart rate patterns, particularly in the second stage of labor, may have pronounced variable decelerations. In breech labor and delivery, compromise to the umbilical circulation may be more frequent but generally is without sequelae. In addition, the intensity and duration of vagal stimulation with its concomitant effects on the fetal heart rate is different than in cephalic labor and delivery. Study of acid–base status at birth demonstrates a tendency to respiratory acidosis in breech vaginal delivery. This might explain a greater proportion of infants with lower Apgar scores at 1 minute. However, the base deficit in these infants generally is within the normal range. 41

Anesthesia considerations dictate the usefulness of regional anesthesia, as opposed to earlier approaches that used a combination of local and general techniques. As shown by Crawford, 42 regional anesthesia prevents premature maternal expulsive efforts, which should enhance the safety of delivery ( Table 14 ).

Table 14. Effect of anesthesia on breech delivery

(Adapted from Weingold AB: The Management of Breech Presentation. In Iffy L, Charles D [eds]: Operative Perinatology, pp 537–553. New York, Macmillan, 1984)

The second stage of labor should be managed under double-setup conditions. A gowned and gloved assistant, as well as anesthesia and pediatrics personnel, should be present. The patient should be instructed and encouraged to push effectively. The fetal heart rate should be continuously monitored. A nullipara should be allowed to push for up to 2 hours, a multipara up to 1 hour. If delivery is not imminent, cesarean delivery should be performed, the diagnosis being a failure of descent.

After lateral flexion of the trunk, the anterior hip is forced against and underneath the symphysis. Expulsion follows, with delivery of the anterior and then the posterior buttock. During “crowning,” an episiotomy should be performed to facilitate delivery.

Using a modified Bracht maneuver, a warm wet towel is placed around the fetal abdomen, and the fetus is grasped on the posterior aspect of the fetal pelvic girdle with care to avoid the fetal kidneys and adrenal. A gentle downward traction is exerted.

After the buttocks are fully expulsed, the back is born by rotation anteriorly. This allows the shoulders to enter the pelvis in the transverse diameter of the pelvic inlet. If there is a failure of anterior rotation, the fetus will be born as a posterior breech, and the sequence of maneuvers used to help in delivery will differ as appropriate.

As the anterior shoulder is seen at the introitus, the operator sweeps the right humerus across the infant's chest. Gentle rotation allows for the posterior shoulder and humerus to be born, completing the Løvset maneuver (Fig. 7).

With the infant delivered to the umbilicus, some authors recommend the use of uterine relaxants to facilitate the remainder of the delivery. The use of general anesthesia with halothane has been supplanted by parenteral betamimetics. We have used small aliquots of intravenous nitroglycerin for this purpose. 43 , 44

Delivery of the after-coming head follows with manual aid or forceps.

A Mauriceau–Smellie–Viet maneuver follows (Fig. 8). The fetus is placed abdomen down on the operator's right arm. The left hand supports the fetal neck. The index and middle fingers of the right hand are placed on the fetal maxilla to help maintain flexion of the head. The assistant may apply suprapubic pressure to expel the after-coming head (Naujok maneuver; Fig. 9). When delivery is further complicated by rotation of the fetal back posteriorly, a Prague maneuver allows for delivery of the occiput posterior breech variant.

Forceps may be used to facilitate delivery of the after-coming head (Fig. 10). Maintenance of head flexion is crucial. Traction is not required. The Piper forceps are specially designed for this task 45 and act as a class 1 lever. Because the fetal head is visible and should be aligned as in an occiput anterior position, any outlet forceps that may be applied as a simple pelvic application are indicated. Elliott forceps are particularly useful in this situation. Use of forceps may be helpful in a nulligravida or when the fetus is small and at term (less than 2500 g).

The infant then should be handed to the pediatrician in attendance. A segment of umbilical cord for acid–base analysis should be routinely obtained. Attention then can be directed to completion of the third stage of labor, as well as the repair of the episiotomy and genital tract lacerations.

A full dictated operative note should be completed at the time of delivery. The entire process of the labor, delivery, and immediate neonatal outcome should be referenced. Mention of each specific step is warranted, along with clinical observations regarding the relative ease or difficulty of the delivery process.

CESAREAN DELIVERY

Most breech-presenting fetuses will be born by cesarean delivery. Attention to the details of delivery are of no less consequence in this group.

When cesarean delivery is selected, the fetus should be evaluated before surgery using bedside ultrasound examination. A careful review of the fetus to diagnose extension of the head, the presence or absence of nuchal arms, and the location of the placenta should be made. Although estimates of fetal weight may be less accurate for breech-presenting fetuses, an estimated fetal weight should be made using a standardized formula. 46 Amniotic fluid volume and location of the umbilical cord also should be observed.

These observations may be important in understanding neonatal concerns after cesarean delivery. They allow both physician and patient to estimate the fetal condition just before birth. Important observations that have been confirmed before delivery include the presence of abnormal postures, broken bones, and the occasional transverse lie (or even an undiagnosed second twin).

Cesarean delivery should be expedited if the patient is in labor. Short-term tocolysis has been used so that the most appropriate anesthesia can be administered. Emergency cesarean delivery, with the greater risks of morbidity for both mother and child, should be chosen as a last resort.

The abdomen generally is opened with a transverse-type incision. Surgical choice of incision may vary by maternal habitus, prior surgery, or operator preference. Any incision may be used, as long as adequate visualization occurs and mobilization of the fetus is expedited.

Palpation of the uterus before the uterine incision should confirm the presentation. A low cervical transverse incision should be made carefully in the midline and extended to a depth necessary to expose the membranes. This is easier to do in practice if the membranes are intact. The important point is that the fetus may be incidentally incised if care is not taken. The infant born by cesarean delivery should be carefully examined after birth in this regard.

The fetus should be rotated (if necessary) so that the back is anterior before delivery. The assistant applies fundal pressure as the operator guides the buttocks up through the uterine incision. The use of force on the fundus allows the after-coming head of the breech fetus to remain in a flexed attitude. This approach also should minimize the loss of flexion of the fetal arms, which may result in a nuchal displacement.

A warm, wet towel is wrapped around the fetal abdomen to protect the fetus from traumatic injury and to mitigate against the onset of breathing movements before delivery.

Thus, by the use of an assistant giving fundal pressure, delivery of a breech fetus at cesarean delivery mirrors an assisted vaginal breech delivery. Avoid total breech extraction at cesarean delivery: it is inherently more of a risk to the fetus than an assisted or spontaneous breech delivery.

As with vaginal delivery, a section of umbilical cord should be sent for acid–base status. Attention is given to the description of the delivery process within the operative report.

PERINATAL OUTCOME

The most important factor in neonatal outcome for all infants is gestational age. This also is true for breech infants.

Many series, generally retrospective, some aided by meta-analysis, have studied the effect of mode of delivery on both immediate and long-term outcome. In the absence of congenital anomalies, laboring fetuses born ultimately by cesarean or vaginal delivery have similar outcomes, which are determined by gestational age and weight. Prolapse of the umbilical cord that occurs before hospitalization or goes unrecognized, although uncommon at term, plays a serious and compromising role for preterm infants. Such also is the case for prolapse of the fetal body through an incompletely dilated cervix. Entrapment of the after-coming head may have serious adverse consequences for the infant who likewise is preterm. This may occur at either cesarean or vaginal delivery.

Infants who are born immediately after admission to labor and delivery also have the greatest risk of asphyxia- and trauma-related injuries manifest in the immediate neonatal period. Women and their fetuses in whom breech presentation is not detected until labor, and who ultimately are delivered by cesarean delivery are subject to the greatest risk of maternal morbidity. 47

Regardless of the rate of cesarean delivery, breech infants have an increased risk of perinatal and neonatal morbidity and mortality. Cesarean delivery plays a role in decreasing but not eliminating this problem. Breech-presenting infants have higher rates of neurologic sequelae than their cephalic peers. The route of delivery plays little role in this difference. 48 .

The International Term Breech Trial 47 , 48 , 49 was undertaken to determine the best approach to term breech delivery management. This trial proved to be limited and controversial in several repects 49 and, subsequently, the PREMODA trial 50 was reported. With a much larger cohort studied, the authors determined that there was no difference in the neonatal outcome between vaginal and cesarean delivery in the term frank breech fetus. Consequently, the American College of Obstetricians and Gynecologists issued a revised Committee Opinion (#340, July 2006) concluding that with adaptation of strict protocol management and based on provider experience, a trial of labor for the term frank breech fetus was an acceptable option. 51 A Practice Bulletin from the Society of Obstetricians and Gynecologists of Canada in 2009 was in agreement with this selective approach to delivery management. 52

The issues encountered in attempting to reach the optimal outcome for every pregnancy complicated by breech presentation include psychological, sociologic, and societal values. A strictly medical paradigm cannot perfectly fit each individual situation. Thus, a variety of approaches conform to the standard of care for medical practice. Resident training in breech delivery should include both the approach to delivery at cesarean section as well as vaginal delivery. 53 All parties involved must understand the risks and benefits of any suggested approaches. Because economic concerns have been emphasized more, a shift of decision making from the individual patient–physician pair to the consideration of the entire population has occurred. Both strategies must be made consistent.

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Obstetric and Newborn Care I

10.02 key terms related to fetal positions.

a. “Lie” of an Infant.

Lie refers to the position of the spinal column of the fetus in relation to the spinal column of the mother. There are two types of lie, longitudinal and transverse. Longitudinal indicates that the baby is lying lengthwise in the uterus, with its head or buttocks down. Transverse indicates that the baby is lying crosswise in the uterus.

b. Presentation/Presenting Part.

Presentation refers to that part of the fetus that is coming through (or attempting to come through) the pelvis first.

(1) Types of presentations (see figure 10-1). The vertex or cephalic (head), breech, and shoulder are the three types of presentations. In vertex or cephalic, the head comes down first. In breech, the feet or buttocks comes down first, and last–in shoulder, the arm or shoulder comes down first. This is usually referred to as a transverse lie.

Figure 10-1. Typical types of presentations.

(2) Percentages of presentations.

(a) Head first is the most common-96 percent.

(b) Breech is the next most common-3.5 percent.

(3) Specific presentation may be evaluated by several ways.

(a) Abdominal palpation-this is not always accurate.

(b) Vaginal exam–this may give a good indication but not infallible.

(d) X-ray–this confirms the presentation, but is used only as a last resort due to possible harm to the fetus as a result of exposure to radiation.

c. Attitude.

This is the degree of flexion of the fetus body parts (body, head, and extremities) to each other. Flexion is resistance to the descent of the fetus down the birth canal, which causes the head to flex or bend so that the chin approaches the chest.

(1) Types of attitude (see figure 10-2).

Figure 10-2. Types of attitudes. A--Complete flexion. B-- Moderate flexion. C--Poor flexion. D--Hyperextension

(a) Complete flexion. This is normal attitude in cephalic presentation. With cephalic, there is complete flexion at the head when the fetus “chin is on his chest.” This allows the smallest cephalic diameter to enter the pelvis, which gives the fewest mechanical problems with descent and delivery.

(b) Moderate flexion or military attitude. In cephalic presentation, the fetus head is only partially flexed or not flexed. It gives the appearance of a military person at attention. A larger diameter of the head would be coming through the passageway.

(c) Poor flexion or marked extension. In reference to the fetus head, it is extended or bent backwards. This would be called a brow presentation. It is difficult to deliver because the widest diameter of the head enters the pelvis first. This type of cephalic presentation may require a C/Section if the attitude cannot be changed.

(d) Hyperextended. In reference to the cephalic position, the fetus head is extended all the way back. This allows a face or chin to present first in the pelvis. If there is adequate room in the pelvis, the fetus may be delivered vaginally.

(2) Areas to look at for flexion.

(a) Head-discussed in previous paragraph, 10-2c(1).

(b) Thighs-flexed on the abdomen.

(d) Arches of the feet-rested on the anterior surface of the legs.

(e) Arms-crossed over the thorax.

(3) Attitude of general flexion. This is when all of the above areas are flexed appropriately as described.

d. Station.

This refers to the depth that the presenting part has descended into the pelvis in relation to the ischial spines of the mother’s pelvis. Measurement of the station is as follows:

(1) The degree of advancement of the presenting part through the pelvis is measured in centimeters.

(2) The ischial spines is the dividing line between plus and minus stations.

(3) Above the ischial spines is referred to as -1 to -5, the numbers going higher as the presenting part gets higher in the pelvis (see figure10-3).

(4) The ischial spines is zero (0) station.

(5) Below the ischial spines is referred to +1 to +5, indicating the lower the presenting part advances.

e. Engagement.

This refers to the entrance of the presenting part of the fetus into the true pelvis or the largest diameter of the presenting part into the true pelvis. In relation to the head, the fetus is said to be engaged when it reaches the midpelvis or at a zero (0) station. Once the fetus is engaged, it (fetus) does not go back up. Prior to engagement occurring, the fetus is said to be “floating” or ballottable.

f. Position.

This is the relationship between a predetermined point of reference or direction on the presenting part of the fetus to the pelvis of the mother.

(1) The maternal pelvis is divided into quadrants.

(a) Right and left side, viewed as the mother would.

(b) Anterior and posterior. This is a line cutting the pelvis in the middle from side to side. The top half is anterior and the bottom half is posterior.

NOTE: Remember that when you are describing the quadrants, view them as the mother would.

(2) Specific points on the fetus.

(a) Cephalic or head presentation.

1 Occiput (O). This refers to the Y sutures on the top of the head.

2 Brow or fronto (F). This refers to the diamond sutures or anterior fontanel on the head.

3 Face or chin presentation (M). This refers to the mentum or chin.

(b) Breech or butt presentation.

1 Sacrum or coccyx (S). This is the point of reference.

2 Breech birth is associated with a higher perinatal mortality.

1 This would be seen with a transverse lie.

2. Scapula (Sc) or its upper tip, the acromion (A) would be used for the point of reference.

(3) Coding of positions.

(a) Coding simplifies explaining the various positions.

1 The first letter of the code tells which side of the pelvis the fetus reference point is on (R for right, L for left).

2 The second letter tells what reference point on the fetus is being used (Occiput-O, Fronto-F, Mentum-M, Breech-S, Shoulder-Sc or A).

3 The last letter tells which half of the pelvis the reference point is in (anterior-A, posterior-P, transverse or in the middle-T).

(b) Each presenting part has the possibility of six positions. They are normally recognized for each position–using “occiput” as the reference point.

1 Left occiput anterior (LOA).

2 Left occiput posterior (LOP).

3 Left occiput transverse (LOT).

4 Right occiput anterior (ROA).

5. Right occiput posterior (ROP).

6 Right occiput transverse (ROT).

1 Occiput at sacrum (O.S.) or occiput at posterior (O.P.).

2 Occiput at pubis (O.P.) or occiput at anterior (O.A.).

(4) Types of breech presentations (see figure10-4).

(a) Complete or full breech. This involves flexion of the fetus legs. It looks like the fetus is sitting in a tailor fashion. The buttocks and feet appear at the vaginal opening almost simultaneously.

A–Complete. B–Frank. C–Incomplete.

(b) Frank and single breech. The fetus thighs are flexed on his abdomen. His legs are against his trunk and feet are in his face (foot-in-mouth posture). This is the most common and easiest breech presentation to deliver.

(c) Incomplete breech. The fetus feet or knees will appear first. His feet are labeled single or double footing, depending on whether 1 or 2 feet appear first.

(5) Observations about positions (see figure 10-5).

(a) LOA and ROA positions are the most common and permit relatively easy delivery.

(b) LOP and ROP positions usually indicate labor may be longer and harder, and the mother will experience severe backache.

Figure 10-5. Examples of fetal vertex presentations in relation to quadrant of maternal pelvis.

1 Breech. This will be upper R or L quad, above the umbilicus.

2 Vertex. This will be lower R or L quad, below the umbilicus.

(d) An occiput in the posterior quadrant means that you will feel lumpy fetal parts, arms and legs (see figure 10-5 A). If delivered in that position, the infant will come out looking up.

(e) An occiput in the anterior quadrant means that you will feel a more smooth back (see figure 10-5 B). If delivered in that position, the infant will come out looking down at the floor.

Distance Learning for Medical and Nursing Professionals

Variation in fetal presentation

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Citation, DOI, disclosures and article data

At the time the article was created The Radswiki had no recorded disclosures.

At the time the article was last revised Yuranga Weerakkody had no financial relationships to ineligible companies to disclose.

Delivery presentations
Variation in delivary presentation
Abnormal fetal presentations

There can be many variations in the fetal presentation which is determined by which part of the fetus is projecting towards the internal cervical os . This includes:

cephalic presentation : fetal head presenting towards the internal cervical os, considered normal and occurs in the vast majority of births (~97%); this can have many variations which include

left occipito-anterior (LOA)

left occipito-posterior (LOP)

left occipito-transverse (LOT)

right occipito-anterior (ROA)

right occipito-posterior (ROP)

right occipito-transverse (ROT)

straight occipito-anterior

straight occipito-posterior

breech presentation : fetal rump presenting towards the internal cervical os, this has three main types

frank breech presentation (50-70% of all breech presentation): hips flexed, knees extended (pike position)

complete breech presentation (5-10%): hips flexed, knees flexed (cannonball position)

footling presentation or incomplete (10-30%): one or both hips extended, foot presenting

other, e.g one leg flexed and one leg extended

shoulder presentation

cord presentation : umbilical cord presenting towards the internal cervical os

1. Fox AJ, Chapman MG. Longitudinal ultrasound assessment of fetal presentation: a review of 1010 consecutive cases. Aust N Z J Obstet Gynaecol. 2006;46 (4): 341-4. doi:10.1111/j.1479-828X.2006.00603.x - Pubmed citation
2. Merz E, Bahlmann F. Ultrasound in obstetrics and gynecology. Thieme Medical Publishers. (2005) ISBN:1588901475. Read it at Google Books - Find it at Amazon

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Published: 02 May 2024

PSFHS: Intrapartum ultrasound image dataset for AI-based segmentation of pubic symphysis and fetal head

Gaowen Chen ORCID: orcid.org/0000-0003-0714-7155 1 na1 ,
Jieyun Bai ORCID: orcid.org/0000-0002-2847-350X 2 , 3 na1 ,
Zhanhong Ou 2 ,
Yaosheng Lu 2 &
Huijin Wang 2

Scientific Data volume 11 , Article number: 436 ( 2024 ) Cite this article

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Medical imaging
Physical examination

During the process of labor, the intrapartum transperineal ultrasound examination serves as a valuable tool, allowing direct observation of the relative positional relationship between the pubic symphysis and fetal head (PSFH). Accurate assessment of fetal head descent and the prediction of the most suitable mode of delivery heavily rely on this relationship. However, achieving an objective and quantitative interpretation of the ultrasound images necessitates precise PSFH segmentation (PSFHS), a task that is both time-consuming and demanding. Integrating the potential of artificial intelligence (AI) in the field of medical ultrasound image segmentation, the development and evaluation of AI-based models rely significantly on access to comprehensive and meticulously annotated datasets. Unfortunately, publicly accessible datasets tailored for PSFHS are notably scarce. Bridging this critical gap, we introduce a PSFHS dataset comprising 1358 images, meticulously annotated at the pixel level. The annotation process adhered to standardized protocols and involved collaboration among medical experts. Remarkably, this dataset stands as the most expansive and comprehensive resource for PSFHS to date.

Automated body organ segmentation, volumetry and population-averaged atlas for 3D motion-corrected T2-weighted fetal body MRI

The Dresden Surgical Anatomy Dataset for Abdominal Organ Segmentation in Surgical Data Science

AI supported fetal echocardiography with quality assessment

Background & summary.

Detecting maternities at risk of requiring a cesarean section is paramount in enhancing perinatal outcomes and maternal satisfaction during childbirth. Prolonged labor or failure to progress is one of the common indications that causes approximately one-third of all cesarean deliveries, underscoring the vital need for precise prediction of prolonged labor to mitigate the occurrence of unplanned emergency cesarean procedures. Notably, the prevalence of cesarean section rates has witnessed a recent increase, often attributed to indications concerning the position of the fetal head (FH) and the progression of labor 1 .

Traditional methods involving subjective digital vaginal examinations for ascertaining FH position, rotation, and descent during delivery have demonstrated a lack of accuracy at times 2 . In this context, intrapartum transperineal ultrasound has emerged as an efficacious approach for monitoring FH descent. A critical advancement offered by this technique is the angle of progress (AOP), which serves as an objective, accurate, and reproducible indicator. Notably surpassing the limitations of digital vaginal examination 3 , the AOP offers insight into the relationship between the pubic symphysis (PS) and FH (PSFH). According to the practice guideline of the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG), AOP is measured on a static 2D ultrasound image and is defined as the angle the angle between the long axis of the pubic bone and a line from the lowest edge of the pubic symphysis that tangentially touches the deepest bony part of the fetal skull. Research indicates that an AoP greater than or equal to 120 degrees is closely linked with a high chance of spontaneous vaginal delivery. Therefore, Therefore, AoP measured based on a single ultrasound image can be used as a predictive indicator of the mode of delivery.

The first step in interpreting the morphometrics is performing PSFH segmentation (PSFHS) - extracting visible PSFH contours from transperineal ultrasound images. However, PSFHS is a challenging task, involving accurate identification and delineation of the PSFH boundaries. FHs can vary widely in shape and orientation during different stages of labor, and surrounding structures like amniotic fluid and placenta can overlap with or obstruct parts of the head, introducing segmentation ambiguity. Additionally, the size and position of PSFH can vary significantly among individuals, making it difficult to develop a single generalized segmentation model. The inherent characteristics of ultrasound images, such as poor resolution, noise, and artifacts, further complicate the PSFHS process, especially during the dynamic changes in relative positions of PS and FH during the second stage of labor.

To address these challenges, automatic segmentation with Artificial Intelligence (AI) offers a promising approach 4 . Modifications to UNet structures have been introduced, incorporating attention mechanisms for improved detail capture 5 , 6 . Notably, Bai et al . devised a dual decoder strategy integrating traditional and deformable convolutions to concurrently extract morphological and global features 7 , 8 . Beyond architectural enhancements, Lu et al . explored the use of a shape-constrained loss function, reinforcing the UNet variant’s resilience to noise through the integration of a convex shape prior 9 . Despite the commendable performance of these UNet variations on proprietary datasets, their comparative evaluation remains challenging due to dataset diversity and size constraints. For example, Lu et al . released the JNU-IFM dataset 10 . Images of the JNU-IFM were acquired with the ObEye system from 51 pregnant women and collected from NanFang Hospital of Southern Medical University 10 . However, the development of AI models relies heavily on datasets from multiple centers, involving different patients, and sourced from various ultrasound devices. These factors significantly enhance the model’s performance, generalizability, and practical applicability in real-world clinical settings. Here are the key reasons why such diverse datasets are important: (1) Different centers may have patient populations with varying demographics, disease prevalence, and comorbidities; (2) Ultrasound devices from different manufacturers or even different models from the same manufacturer can produce images with varying qualities, resolutions, and characteristics; (3) Different centers might have varying protocols for image acquisition, patient preparation, and even image annotation standards; and (4) Images from different sources can have various types of noise, artifacts, or quality issues. A model trained on a diverse dataset is likely to generalize better to unseen data, reducing the risk of overfitting to specific characteristics of the training data. This is crucial for medical applications where the cost of errors can be very high. Therefore, larger and more comprehensive datasets are essential 8 .

To address these challenges and accelerate progress in AI research, it is imperative to promote data sharing and establish more comprehensive and representative datasets. In line with this objective, a proposed PSFHS dataset has been introduced, encompassing intrapartum transperineal ultrasound images that have been meticulously annotated at the pixel level through standard crowdsourcing among medical professionals. 1358 images from 1124 patients were gathered to form the PSFHS dataset. The accuracy of the pixelwise annotation, carried out by a group of trained students, was verified by expert physicians. This dataset is expected to facilitate the monitoring of labor progression through computer-aided systems and promote the practical implementation of technology in clinical settings, ultimately contributing to enhanced childbirth outcomes and improved care for both mother and fetus.

Subject characteristics

This retrospective image collection included 1124 pregnant women from two different medical institutions. Inclusion criterias were defined as: singleton pregnancy at term gestation (37 weeks or more), fetus in cephalic presentation, absence of documented fetal malformations. There are two parts in the PSFHS dataset: 1045 images from 1040 patients of Zhujiang Hospital of Southern Medical University, 313 images from 84 pregnant women from the Department of Obstetrics and Gynecology of the First Affiliated Hospital of Jinan University (Fig. 1a ). This study received approval from the institutional review boards of Zhujiang Hospital of Southern Medical University (No. 2023-SYJS-023) and the First Affiliated hospital of Jinan University (No. JNUKY-2022-019). Informed consent was waived because of the retrospective nature of the study and the analysis used anonymous medical image data.

Workflow of the establishment of the proposed dataset. ( a ) 1358 images from 1124 pregnant women were collected. ( b ) The annotation team was made up of 2 physicians and 18 annotators. (c) For each ultrasound image, two annotators conducted initial annotation. These segmentations were merged and then adjusted by a physician to obtain the ground truth. ( d ) Based on the final ground truth of PSFH, AOP measurement consisted of ellipse fitting, line identification, and AOP calculation.

Image acquisition

Ultrasound acquisitions were performed using a portable machine equipped with a 3.5 MHz probe. The ‘ObEye’ system (Guangzhou, China; http://lian-med.com ) and the Esaote My Lab were used in the First Affiliated Hospital of Jinan University and Zhujiang Hospital of Southern Medical University, respectively. During each acquisition, the operator positioned the probe longitudinally in the translabial area to visualize both the PS horizontally in the upper central part of the image and the edges of the FH in the lower part 11 . These original images were cropped to remove sensitive information about patients.

Image annotation

The team responsible for annotations included 2 proficient physicians and 18 students specializing in biomedical studies (refer to Fig. 1b ). Before commencing their tasks, annotators received comprehensive training that involved familiarizing them with the structures of PSFH and the key aspects of ultrasound images. This training was facilitated through a combination of online sessions and in-person guidance by the physicians. Each annotator was assigned 15 test images, which were subsequently assessed by the physicians. If the annotations were deemed inadequate, the images were returned to the respective student for refinement. Annotators were instructed to utilize the pencil tool in Pair ( https://www.aipair.com.cn/ ) for precise pixel-wise segmentation. They used red color for the pixel outlines of PS and green for the contour pixels of FH. In instances where the contours appeared fragmented or discontinuous, annotators were instructed to ensure that the contours maintained a complete elliptical shape. This instruction was essential considering the ultimate clinical application’s requirement to calculate AOP based on the segmented PSFH contours. The final segmentation ground truth was represented by a three-color image, where red pixels denoted PS, green pixels represented FH, and black pixels indicated the background. During the official annotation phase, each image was annotated by two annotators. Any overlapping pixels annotated by both annotators were further reviewed and adjusted by a highly experienced physician with a decade of expertise (refer to Fig. 1c ). Note: Dropped artifacts in ultrasound images can significantly impact the quality and accuracy of the images, leading to potential errors in annotation. If artifact annotation may help to develop application-oriented robust algorithms, such as uncertain segmentation algorithms.

Morphological parameters

Class imbalance is a common issue in image segmentation tasks that significantly affects the performance of deep learning models. When there is a class imbalance, it means that the number of pixels belonging to one class significantly outnumbers the pixels belonging to other classes. The pixel ratio of background to target (or among various targets) is a critical metric for understanding class imbalance. In the PSFHS dataset, the pixel proportions of PS, FH and background are, 1.78% ± 0.66%, 14.55 ± 5.73%, and 83.66 ± 6.27%, respectively. Based on the ground truth of PSFH, ellipse fitting is performed and thereby AOP is measured according to its definition—the angle between the longitudinal axis of the pubic symphysis and a line originating from its inferior edge to the leading edge of the fetal cranium tangentially (Fig. 1d ) 7 , 9 . AOP is a predictor of the mode of delivery and the average value of AOP in the PSFHS dataset is 98.33° ± 21.11°.

Data Records

All data records 12 are available as files on the web page https://doi.org/10.5281/zenodo.10969427 . The unzipped file folder of this dataset contains the original transperineal ultrasound images and annotation ground truth images. The unzipped file is organized into 2 folders, named “image_mha” and “label_mha”, that contain original transperineal ultrasound images and corresponding ground truth images, respectively. The images in these 2 folders are stored, named and arranged according to the same rule, where a specific image in the “label_mha” folder is the ground truth of the image with the same name in the “image_mha” folder. Images are named as “n.mha”, where “n” means the number of images. In the dataset, there are 1358 images (“n” from 03744 to 05101) of 1124 pregnant women. The images in the “image_mha” folder contain pixels labelled as 0, 1, or 2, where 0 represents the background, 1 represents the PS, and 2 represents the FH. These data can be accessed using the software “Insight Segmentation and Registration Toolkit”, available at https://itk.org/ .

Technical Validation

In this research, each ultrasound image underwent double annotation, followed by refinement by a medical professional. This process prompted the investigation of three distinct types of consistencies: intra-annotator consistency, referring to the same annotator at different time points; inter-annotator consistency among annotators at the same level; and inter-annotator consistency among annotators at different levels 13 .

To assess the intra-annotator consistency of the different annotators across various instances, a set of 40 images was selected from the complete dataset. These 40 images were annotated twice by three different annotators, including one physician and two others, on separate occasions. The Dice coefficient was then calculated between the annotations from the first and second rounds. The mean Dice coefficient for all 40 images and three annotators was 0.8817, with a confidence interval of 0.8502–0.9002.

To evaluate the inter-annotator consistency among annotators at the same level, discrepancies were assessed by computing the Dice coefficient between the annotations produced by the two annotators. The resulting mean Dice coefficient was 0.8750 (0.8520–0.8886).

Additionally, for the inter-annotator consistency among annotators at different levels, emphasis was placed on the first annotations. The Dice coefficient was used to measure the concordance between the physician’s mask and the annotations from the two annotators. The mean Dice coefficient for this scenario was determined to be 0.8720 (0.8520–0.8904).

Furthermore, to examine the intra-annotator consistency of the same annotator at different time points, the Dice coefficient was calculated between the first and second annotations. The resulting mean Dice coefficients were 0.8953 for the physician, 0.8811 for annotator 1, and 0.8689 for annotator 2.

Upon thorough analysis of both the original annotations and the illustrative set, it was concluded that the annotations demonstrated stability and consistency not only within a single annotator over different instances but also across various annotators. These findings collectively provide a strong basis for accurate annotation and reproducible PSFHS, as detailed in Table 1 .

Usage Notes

The whole dataset used for the PSFHS challenge of MICCAI2023 ( https://ps-fh-aop-2023.grand-challenge.org/ ) includes two parts 12 , 14 , 15 : one is this PSFHS dataset ( https://doi.org/10.5281/zenodo.10969427 ) 12 and another is from the JNU-IFM dataset ( https://doi.org/10.6084/m9.figshare.14371652 ) 16 . These images in the PSFHS dataset can also be used for the Intrapartum Ultrasound Grand Challenge (IUGC) 2024 of MICCAI 2024 ( https://codalab.lisn.upsaclay.fr/competitions/18413 ).

Code availability

No novel code was used in the construction of the PSFHS dataset.

Sandall, J. et al . Short-term and long-term effects of caesarean section on the health of women and children. Lancet (London, England) 392 , 1349–1357, https://doi.org/10.1016/s0140-6736(18)31930-5 (2018).

Article PubMed Google Scholar

Seval, M. M. et al . Comparison of effects of digital vaginal examination with transperineal ultrasound during labor on pain and anxiety levels: a randomized controlled trial. Ultrasound in Obstetrics & Gynecology 48 , 695–700, https://doi.org/10.1002/uog.15994 (2016).

Article CAS Google Scholar

Ghi, T. et al . ISUOG Practice Guidelines: intrapartum ultrasound. Ultrasound in Obstetrics & Gynecology 52 , 128–139, https://doi.org/10.1002/uog.19072 (2018).

Ramirez Zegarra, R. & Ghi, T. Use of artificial intelligence and deep learning in fetal ultrasound imaging. Ultrasound in Obstetrics & Gynecology 62 , 185–194, https://doi.org/10.1002/uog.26130 (2023).

Fiorentino, M. C., Villani, F. P., Di Cosmo, M., Frontoni, E. & Moccia, S. A review on deep-learning algorithms for fetal ultrasound-image analysis. Medical image analysis 83 , 102629, https://doi.org/10.1016/j.media.2022.102629 (2023).

Chen, Z., Ou, Z., Lu, Y. & Bai, J. Direction-guided and multi-scale feature screening for fetal head–pubic symphysis segmentation and angle of progression calculation. Expert Systems with Applications 245 , 123096, https://doi.org/10.1016/j.eswa.2023.123096 (2024).

Article Google Scholar

Bai, J. et al . A framework for computing angle of progression from transperineal ultrasound images for evaluating fetal head descent using a novel double branch network. Frontiers in physiology 13 , 940150, https://doi.org/10.3389/fphys.2022.940150 (2022).

Article PubMed PubMed Central Google Scholar

Zhou, M. et al . The segmentation effect of style transfer on fetal head ultrasound image: a study of multi-source data. Medical & biological engineering & computing 61 , 1017–1031, https://doi.org/10.1007/s11517-022-02747-1 (2023).

Lu, Y. et al . Multitask Deep Neural Network for the Fully Automatic Measurement of the Angle of Progression. Computational and mathematical methods in medicine 2022 , 5192338, https://doi.org/10.1155/2022/5192338 (2022).

Lu, Y. et al . The JNU-IFM dataset for segmenting pubic symphysis-fetal head. Data in brief 41 , 107904, https://doi.org/10.1016/j.dib.2022.107904 (2022).

Article CAS PubMed PubMed Central Google Scholar

Brunelli, E. et al . The role of the angle of progression in the prediction of the outcome of occiput posterior position in the second stage of labor. American journal of obstetrics and gynecology 225 , 81.e81–81.e89, https://doi.org/10.1016/j.ajog.2021.01.017 (2021).

Bai, J. PSFHS. Zenodo. https://doi.org/10.5281/zenodo.10969427 (2024).

Jin, K. et al . FIVES: A Fundus Image Dataset for Artificial Intelligence based Vessel Segmentation. Scientific data 9 , 475, https://doi.org/10.1038/s41597-022-01564-3 (2022).

Qiu, R., Zhou, M., Bai, J., Lu, Y. & Wang, H. HPSSP-Net: An Efficient Lightweight Network for Identifying Head-Pubic Symphysis Standard Plane from Intrapartum Ultrasound Images. Medical & Biological Engineering & Computing (In Press) .

Bai, J., Ou, Z., Lu, Y., Ni, D. & Chen, G. Pubic Symphysis-Fetal Head Segmentation from Transperineal Ultrasound Images. International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI) 2023 (MICCAI 2023). Zenodo https://doi.org/10.5281/zenodo.7861699 (2023).

Lu, Y., Bai, J., Zhou, M. & Zhou, M. The JNU-IFM dataset for segmenting symphysis pubis-fetal head. Figshare https://doi.org/10.6084/m9.figshare.14371652 (2022).

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Acknowledgements

The work is funded by the Natural Science Foundation of Guangdong Province (2024A1515011886 and 2023A1515012833), Guangzhou Municipal Science and Technology Bureau Guangzhou Key Research and Development Program (2024B03J1283 and 2024B03J1289), the Guangdong Health Technology Promotion Project (2022 NO.132), the Science and Technology Program of Guangzhou (202201010544) and the China Scholarship Council. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We would thank these doctors and students for their contributions in data annotation (Minghong Zhou, Chao Yuan, Mengqiang Zhou, Xiaosong Jiang, Dengjiang Zhi, Ruiyu Qiu, Di Qiu, Zhanhang Song, Shen Yu, Hao Yi, Hao Liu, Jingbo Rong, Xiaoyan Xie and Jianguo Qi).

Author information

These authors contributed equally: Gaowen Chen, Jieyun Bai.

Authors and Affiliations

Obstetrics and Gynecology Center, Zhujiang Hospital, Southern Medical University, Guangzhou, China

Gaowen Chen

Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou, China

Jieyun Bai, Zhanhong Ou, Yaosheng Lu & Huijin Wang

Auckland Bioengineering Institute, the University of Auckland, Auckland, New Zealand

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Contributions

Gaowen Chen: Project administration, Conducting intrapartum ultrasound, Manual segmentation, Writing. Jieyun Bai: Conceptualization, Project administration, Manual segmentation, Writing, Reviewing, Visualization. Zhanhong Ou: Conceptualization, Manual segmentation, Methodology, Reviewing. Yaosheng Lu: Conceptualization, Methodology, Project administration, Methodology, Reviewing. Huijin Wang: Conceptualization, Funding acquisition, Project administration, Reviewing.

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Correspondence to Jieyun Bai or Yaosheng Lu .

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Chen, G., Bai, J., Ou, Z. et al. PSFHS: Intrapartum ultrasound image dataset for AI-based segmentation of pubic symphysis and fetal head. Sci Data 11 , 436 (2024). https://doi.org/10.1038/s41597-024-03266-4

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DOI : https://doi.org/10.1038/s41597-024-03266-4

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Fetal presentation: Breech, posterior, transverse lie, and more
Fetal position refers to whether the baby is facing your spine (anterior position) or facing your belly (posterior position). Fetal position can change often: Your baby may be face up at the beginning of labor and face down at delivery. Here are the many possibilities for fetal presentation and position in the womb.
Fetal presentation before birth
Frank breech. When a baby's feet or buttocks are in place to come out first during birth, it's called a breech presentation. This happens in about 3% to 4% of babies close to the time of birth. The baby shown below is in a frank breech presentation. That's when the knees aren't bent, and the feet are close to the baby's head.
Fetal Positions For Birth: Presentation, Types & Function
Possible fetal positions can include: Occiput or cephalic anterior: This is the best fetal position for childbirth. It means the fetus is head down, facing the birth parent's spine (facing backward). Its chin is tucked towards its chest. The fetus will also be slightly off-center, with the back of its head facing the right or left.
Fetal Presentation, Position, and Lie (Including Breech Presentation
Variations in fetal presentation, position, or lie may occur when. The fetus is too large for the mother's pelvis (fetopelvic disproportion). The uterus is abnormally shaped or contains growths such as fibroids. The fetus has a birth defect. There is more than one fetus (multiple gestation).
Fetal Presentation, Position, and Lie (Including Breech Presentation)
Fetal lie: Relation of the fetus to the long axis of the uterus; longitudinal, oblique, or transverse. Normal fetal lie is longitudinal, normal presentation is vertex, and occiput anterior is the most common position. Abnormal fetal lie, presentation, or position may occur with. Fetopelvic disproportion (fetus too large for the pelvic inlet)
Delivery, Face and Brow Presentation
The term presentation describes the leading part of the fetus or the anatomical structure closest to the maternal pelvic inlet during labor. The presentation can roughly be divided into the following classifications: cephalic, breech, shoulder, and compound. Cephalic presentation is the most common and can be further subclassified as vertex, sinciput, brow, face, and chin.
Vertex Presentation: Position, Birth & What It Means
Vertex Presentation. A vertex presentation is the ideal position for a fetus to be in for a vaginal delivery. It means the fetus is head down, headfirst and facing your spine with its chin tucked to its chest. Vertex presentation describes a fetus being head-first or head down in the birth canal.
Fetal Positions for Labor and Birth
The left occiput anterior (LOA) position is the most common in labor. In this position, the baby's head is slightly off-center in the pelvis with the back of the head toward the mother's left thigh. The right occiput anterior (ROA) presentation is also common in labor.
Fetal Presentation: Baby's First Pose
The position in which your baby develops is called the "fetal presentation.". During most of your pregnancy, the baby will be curled up in a ball - that's why we call it the "fetal position.". The baby might flip around over the course of development, which is why you can sometimes feel a foot poking into your side or an elbow ...
Your Guide to Fetal Positions before Childbirth
Here's your guide to the different positions, or fetal presentations, your baby might be in before birth. Why Does My Baby's Position Matter? Vaginal births can become complicated quickly—and the odds of complication are much higher if your little one isn't in an ideal position, or presentation, for delivery. For instance, if your baby ...
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Fetal Position
Fetal position reflects the orientation of the fetal head or butt within the birth canal. The bones of the fetal scalp are soft and meet at "suture lines." Over the forehead, where the bones meet, is a gap, called the "anterior fontanel," or "soft spot." This will close as the baby grows during the 1st year of life, but at birth, it is open.
Presentation (obstetrics)
compound presentation—when any other part presents along with the fetal head; Related obstetrical terms Attitude. Definition: Relationship of fetal head to spine: flexed, (this is the normal situation) neutral ("military"), extended. hyperextended; Position. Relationship of presenting part to maternal pelvis based on presentation.
Abnormal Presentation
Compound presentation means that a fetal hand is coming out with the fetal head. This is a problem because: The amount of baby that must come through the birth canal at one time is increased. There is increased risk of mechanical injury to the arm and shoulder, including fractures, nerve injuries and soft tissue injury.
Abnormal Fetal lie, Malpresentation and Malposition
Abnormal Fetal Lie. If the fetal lie is abnormal, an external cephalic version (ECV) can be attempted - ideally between 36 and 38 weeks gestation. ECV is the manipulation of the fetus to a cephalic presentation through the maternal abdomen. It has an approximate success rate of 50% in primiparous women and 60% in multiparous women.
Compound fetal presentation
Compound presentation is a fetal presentation in which an extremity presents alongside the part of the fetus closest to the birth canal. The majority of compound presentations consist of a fetal hand or arm presenting with the head [ 1 ]. This topic will review the pathogenesis, clinical manifestations, diagnosis, and management of this ...
Abnormal Fetal Lie and Presentation
Fetal presentation is a reference to the part of the fetus that is overlying the maternal pelvic inlet. The most common relationship between fetus and mother is the longitudinal lie, cephalic presentation. ... that a breech baby means a mandatory cesarean section. Whereas there is some truth in this simple association, I strongly believe that ...
10.02 Key Terms Related to Fetal Positions
(a) Cephalic or head presentation. 1 Occiput (O). This refers to the Y sutures on the top of the head. 2 Brow or fronto (F). This refers to the diamond sutures or anterior fontanel on the head. 3 Face or chin presentation (M). This refers to the mentum or chin. (b) Breech or butt presentation. 1 Sacrum or coccyx (S). This is the point of reference.
Variation in fetal presentation
breech presentation: fetal rump presenting towards the internal cervical os, this has three main types. frank breech presentation (50-70% of all breech presentation): hips flexed, knees extended (pike position) complete breech presentation (5-10%): hips flexed, knees flexed (cannonball position) footling presentation or incomplete (10-30%): one ...
Mental Health Is Health: Caring for the Whole Child
These Presentations are intended only to provide general information and need to be adapted for each specific patient based on the practitioner's professional judgment, consideration of any unique circumstances, the needs of each patient and their family, the availability of various resources at the health care institution where the patient ...
PSFHS: Intrapartum ultrasound image dataset for AI-based ...
Inclusion criterias were defined as: singleton pregnancy at term gestation (37 weeks or more), fetus in cephalic presentation, absence of documented fetal malformations.
BioLineRx Announces Poster Presentation on Economic Model Data for
Embryo-fetal Toxicity: Based on its mechanism of action, APHEXDA can cause fetal harm. Advise pregnant women of the potential risk to the fetus. Advise pregnant women of the potential risk to the ...

Breech, posterior, transverse lie: What position is my baby in?

Fetal presentation and position

Head down, facing down (anterior position)

Head down, facing up (posterior position)

Frank breech

Complete breech

Incomplete breech

Single footling breech

Double footling breech

Transverse lie

Oblique lie

What to know if your baby is breech

What's a sunny-side up baby?

What happens to your baby right after birth

How your twins’ fetal positions affect labor and delivery

Where to go next

Appointments at Mayo Clinic

Head down, face down

Head down, face up

Frank breech

Complete and incomplete breech

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Fetal Presentation, Position, and Lie (Including Breech Presentation)

Transverse lie

Breech presentation

Types of breech presentations

Face or brow presentation

Occiput posterior position

Position and Presentation of the Fetus

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Fetal Positions for Labor and Birth

Right or Left Occiput Anterior

Right or Left Occiput Transverse

Tips to Reduce Discomfort

Right or Left Occiput Posterior

How a Doctor Determines Baby's Position

How You Can Determine Baby's Position

Fetal Presentation: Baby’s First Pose

Occiput Anterior

Breech Presentation

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Fetal Presentation, Position, and Lie (Including Breech Presentation)

Position and Presentation of the Fetus

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Breech presentation

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Abnormal Fetal lie, Malpresentation and Malposition

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Identifying Fetal Lie, Presentation and Position

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Abnormal Fetal Lie

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Variation in fetal presentation