Definition - What does Cephalic Presentation mean?
Cephalic presentation refers to the position of the baby inside the mother’s uterus in which the baby’s head is facing down as seen on an ultrasound as well as it is the first part to show during delivery. Cephalic presentation is the most favorable and the most common form of presentation. In a cephalic presentation, the head comes out first with the chin tucked into the baby’s chest. All other presentations are abnormal and pose challenges during delivery.
FertilitySmarts explains Cephalic Presentation
There are a few types of cephalic presentation.
The most common type is the vertex presentation where the baby’s head is bent and the back of the head (called the occiput) leads the way into the mother’s birth canal. Vertex is the highest point of the skull. In most cases of vertex presentation, the back of the baby’s head is toward the front of the mother’s pelvis. This presentation, known as occiput anterior, is considered to be the most ideal position for a vaginal delivery. However, around 5% of babies present in the occiput posterior position rather than the occiput anterior, where the back of the baby’s head faces the mother’s backbone. The baby’s head in this position is not completely bent as it’s in the occiput anterior presentation. Hence, the part that presents first during delivery is larger, making it harder to pass through the birth canal and can eventually give rise to the following complications in both the mother and baby:
- a painful and prolonged labor
- severe lacerations during delivery
- cesarean section
- birth trauma
- cord academia: High levels of acid in the fetal umbilical cord due to oxygen deprivation for an extended period of time, which can further lead to a number of physical and mental delays in the baby after its birth
Sometimes, the head is straight where the face becomes the leading part, known as the face presentation. This type of cephalic presentation is seen in less than 1% of pregnancies at term. There’s a third variety of cephalic presentation called sincipital presentation, in which the large soft spot on the baby’s skull is the presenting part. Very rarely, brows may be the presenting part at delivery. The chin presentation is a variant of the face presentation that occurs when the head is extensively straightened during delivery.
Why is the cephalic presentation most common? This is because of the way the mother’s uterus is designed —the fundus (upper, broader part of the uterus) being larger that causes the baby to adopt a position so that the bulkier and more mobile feet of the baby occupy the upper, broader portion of the uterus and the head moves to the opposite side.