Vertex presentation is a description of how a baby presents during childbirth, in which the baby leads with the back of the head or occiput, so that the head is the first thing into and out of the birth canal. There are actually a number of vertex presentations, and they usually are described as the chin being tucked toward the chest for easier delivery. Of these different types, the left occiput anterior is considered the most desirable delivery, where baby’s face faces towards the mother's right buttock.
The other types of vertex presentation include transverse positions, where the baby’s head faces sideways toward one or the other of mom’s legs. Alternately some children are born face up, where the face points toward the mother’s pubis or angles slightly to the side. This is called occipto-posterior. Even in the desirable occipto-anterior, some children face down to one or the other side instead of presenting straight on.
In most of these instances, vertex presentation of any type can mean a normal delivery. Transverse and occipto-posterior positions may require some intervention, though they are still far preferable to a birth where the baby presents in breech (rear first) or with a shoulder first. There are some arguments about the best way to deliver an occipto-posterior or transverse vertex presentation, and some doctors advocate either turning the baby or using forceps. It should also be noted that a transverse position is more likely to occur in pre-term labor.
Quite a bit has been written about trying to get a baby into the most desirable vertex presentation prior to birth, and there are a number of recommendations arising from many studies conducted by midwives. Particularly in the last month of pregnancy, doctors and midwives often advise women to spend time on their hands and knees. This seems to have a positive effect on creating optimum positioning. Other suggestions include being certain to sleep on the side instead of on the back, and to not lie down with the legs up.
These recommendations may be especially important for women who have already had a child. A fair number of women giving birth to a second child have a variation of the vertex presentation, where the baby is born brow first, instead of presenting with the back of the head first. Though brow presentation might result in a normal birth, the head is flexed up instead of the chin to chest arrangement. If the head doesn’t flex down into vertex, many physicians prefer to manage this with c-section. Typically, forceps delivery is not recommended with this presentation.