Contents
Presentation of the summit
This position, head down flexed, is the most common (95%) and the most favorable for birth. Indeed, to engage as best as possible in the maternal pelvis, which is not very large (12 cm in diameter), the baby’s head must be made as small as possible and therefore bend as much as possible. In this position, the baby’s chin is against his chest, and the diameters reduced to 9,5 cm. Easier then to descend and turn. Expulsion takes place occiput under the pubic symphysis. Your baby comes out looking at the ground!
The posterior presentation
In this variant of the summit presentation, the baby has the top of his skull (the occiput) facing the posterior part of the maternal pelvis. Its head is less flexed and therefore has larger diameters at the entrance to the pelvis. The rotation of the head, which must come to be wedged under the pubis for the exit, is more difficult and it sometimes happens that it is not done in the right direction. This causes longer labor and localized pain in the lower back: the famous “childbirth by the kidneys”!
The presentation of the face
The work in this position is a little more delicate and longer but goes normally in more than 70% of the cases. Indeed, instead of being well flexed, the baby’s head is completely thrown back, the occiput being in contact with the back. The obligatory condition to avoid the caesarean: that the chin turns forward and is wedged under the symphysis, otherwise the diameters of the head exceed that of the maternal pelvis and it risks becoming locked. Because the baby’s face comes first as it descends into the maternal pelvis, there is often swelling of the lips and cheeks after birth. Rest assured, it goes away in a few days.
The presentation of the front
This is the most unfavorable head-down position. The fetal head is in an intermediate position, neither flexed nor deflected and has diameters incompatible with the maternal pelvis. The only solution: the cesarean section, without waiting.
Read also the file on “Giving birth by cesarean”
The seat presentation
This longitudinal presentation buttocks down is found at the end of pregnancy in 3 to 4% of fetuses. Your baby can be seated cross-legged, this is called a full seat or more frequently a complete seat with the legs extended in front of the trunk, the feet at the height of the head. Childbirth by natural means will only be accepted at the cost of a certain number of precautions with which it is necessary to surround oneself. The main one: the diameters of the fetal head must coincide with those of the maternal pelvis. Your doctor will therefore order an ultrasound to measure the diameters of the baby’s head and a radiopelvimetry to make sure your pelvis is large enough. The danger indeed comes from the risk of retention of the head after the exit of the body of the baby. As a result, many doctors prefer to take your baby out by cesarean section as a precaution. When the baby is in an incomplete breech, the risk of congenital hip dislocation is more frequent. A careful examination will therefore be carried out by the pediatrician in the maternity hospital and an ultrasound and radiological control a few months later.
The transverse or shoulder presentation
This presentation is fortunately very rare at the time of labor. The baby is in a horizontal position and a natural delivery is impossible. The only option is therefore a quick cesarean. At the end of pregnancy, an external version can nevertheless be tried.