In childbirth, presentation refers to the direction a baby is facing, or what part of their body is leading out right before delivery. How a baby is facing can help the delivery go smoothly or cause problems, for both mother and baby.
Your baby's head can be in several positions that affect labor. To determine the position of the baby, your doctor will feel for their head in relation to your pelvis. The key to getting the head through the pelvis is to pass the smallest part of the head through the smallest parts of the pelvis.
Types of presentations
Most babies come out head-first, facing the mother’s back, with chin tucked in. This is called a cephalic presentation. Other positions may keep the head from passing through, depending on:
- the shape of the mother's pelvis
- the shape of the baby's head
- how much the baby's head can mold or change shape
- how much the mother's pelvic floor muscles can contract and relax
Some other types of presentations are:
In this presentation, the baby is head-first, facing toward the mother’s abdomen. This presentation commonly causes problems during delivery. Several factors increase the risk of an occiput posterior position, including a narrow pelvis in the mother.
In most cases, no intervention is necessary to deliver a baby in this position. But if labor does not progress normally despite adequate contractions and pushing by the mother, the baby's head can sometimes be rotated into the anterior or face-down position, either manually or with forceps. If this can't be done and the baby is still not progressing through the birth canal, a cesarean delivery may be needed.
Brow or face
In brow or face presentations, the baby enters the birth canal brow-first and their head and neck are hyperextended, whereas in a cephalic presentation the chin is tucked in. This presentation is much less common than cephalic and occiput posterior presentations, and commonly occurs when:
- the fetal membranes rupture prematurely
- the baby's head is large
- the mother has previously given birth
Most brow presentations change to cephalic or occiput posterior presentations on their own, before the second stage of labor, the pushing phase. If labor continues to progress during the second stage, vaginal delivery may be attempted. However, if labor is arrested, there should be no attempt to manipulate the head manually or with forceps. The baby will most likely be delivered by cesarean.
A compound presentation occurs when your baby's arm or leg is next to the main presenting part, usually the head. Labor can generally proceed normally without any manipulation, which might harm the baby or cause the umbilical cord to slip through the cervix. Usually, as labor progresses, the compound presenting part will retract and the baby's head will ultimately present. Sometimes your obstetrician will pinch the baby's finger to stimulate a reflex contraction which will relieve the compound presentation.
Serious problems can occur for both mother and baby during labor and delivery of a transverse presentation. In this presentation, the baby is sideways in the uterus, perpendicular to the opening of the birth canal. Most transverse babies can’t be delivered vaginally because they are too wide to pass through the birth canal. This can rupture the birth canal and cause a life-threatening situation for both mother and baby.
Before labor, transverse presentations are usually not dangerous because the baby often is in the process of moving from a breech, or bottom-first, to a cephalic presentation, or vice versa. But during labor, a transverse presentation should be converted to either a cephalic or breech presentation, or a cesarean should be performed. The process of manipulating the fetus into a cephalic presentation is called an external cephalic version.
In this bottom-first presentation, the baby’s buttocks are facing the birth canal. Breech births aren’t as common as cephalic presentations and occur in about 1 out of every 25 births, according to the American Pregnancy Association. There are a few kinds of breech presentations, including:
- complete breech, where the baby’s buttocks are facing down and both legs are folded up, knees bent, feet toward the bottom
- frank breech, where the baby’s buttocks are facing down and their legs are straight up, feet near the baby’s head
- footling breech, where one or both of the baby’s feet are facing down and will deliver before the rest of the body
Situations that can increase the chances of a breech birth are:
- second or later pregnancy
- having twins or multiples
- history of premature deliveries
- abnormal shape of the uterus
- too much or too little amniotic fluid
- placenta previa, where the placenta lies low in the uterus and covers the cervix to some degree
One risk of having a breech birth is that the umbilical cord can wrap around the baby’s neck, as it is the last part to come out. Sometimes a baby in a breech presentation can be manipulated to turn around and face forward, but sometimes not. Constant monitoring of the baby’s heart rate is critical. A baby can be born breech, but if your doctor foresees any issues, you may need to have a cesarean delivery.
Many types of presentations are possible right before childbirth. The most common is a cephalic presentation, head-first, facing down, with the baby’s chin tucked in. Many factors affect presentation. In some cases, your baby can be manipulated to move into a different position. Even if your baby is in a position other than cephalic, they can still come through the birth canal without harm. Your doctor and nurses will be constantly monitoring your and your baby’s vital signs. If trouble arises, they may need to do a cesarean to keep you and your baby safe.