The work is almost always shorter and easier if your baby is head down, the back of his head turned slightly to the front of your belly. We talk about previous or cephalic position. The vast majority of babies adopted this position during pregnancy.
Cephalic position, your baby nestles in the curve of your pelvis. While working, he curls up and goes the chin in the chest. The labor and birth are normally easier if your baby is in this position because:
The top of the baby's head exerts a steady pressure on the cervix during contractions. This helps the cervix to widen and to produce the hormones you need for work.
At the time of the push, the baby growing in the basin so that the smallest part of his head comes first.
When the baby arrived at the bottom of the basin, he turns his head slightly, the larger part of it then occupying the larger part of the basin. His neck may well slip under the pubic bone. At the time of birth, his face enters the area between the vagina and perineum.
What is a posterior position?
We talk about posterior position when your baby upside down and his spine is facing yours. By the beginning of work, approximately one baby in 10 is in this position back to back, or posterior.
Most babies back to back are born vaginally, but this position can make work difficult, especially if the baby's chin up and not down. Some consequences described by some but are not unanimous (so you can escape it):
you may have back pain, your baby's skull pushing against your spine,
you may lose waters in early labor,
work may be longer and slower,
you might want to push until your cervix is fully dilated
Your baby may turn spontaneously at the end of expansion. The obstetrician-gynecologist can help her but it's not always possible. But the baby may not turn at all. In this case, it will be born with the face facing you. Forceps or suction may be needed to help him out.
Why are some babies posterior position they?
Some Anglo-Saxon authors suggest the shape of the basin (oval or heart-shaped rather than round) to explain the baby's posterior position. Others speak of the lifestyle of Western women, mostly sitting (in the office, watching TV etc..): The pelvis is tilted backwards, which encourages the heaviest part of your baby (back his head and spine) to pivot rearwardly The French obstetrician-gynecologists are more cautious and do not advance any particular explanation.
Can I help my baby to take a forward position before delivery?
You may have heard of a technique - Anglo Saxon - called optimal fetal positioning (POF). This is to encourage your baby to take a forward position by changing your posture, especially when seated. The goal is to try to tilt the pelvis forward rather than backward, so if you're sitting, make sure your knees are always lower than your hips. Studies to date on the POF show that taking a position on all fours, for 10 minutes twice a day in late pregnancy, may promote earlier position of the baby.
Can I improve my baby's position during labor?
If your baby is in a posterior position when labor starts, you can continue to prefer vertical postures, squatting or leaning forward to try to help your baby to turn and relieve your pain. It is common that babies change position during labor, most of them adopting a prior position before the pushing phase, regardless of their position in early labor.
It is also necessary that the medical team, including midwives, are agreed and available to advise you and guide you. Otherwise, it is the obstetrician who judges what to do: it can help the baby to turn, but it does not work every time!
And if my baby is breech?
Sometimes, indeed, that the baby has not done his pirouette in late pregnancy and occurs in the butt down, feet on the face (known as breech). The obstetrician then offers an "external version". Conducted during the eighth month, it is to put pressure on the pubis, to go back and buttocks on top of the uterus to lower the head. It's not really painful, but not very pleasant either. Sometimes the baby turns ... but it puts ass down before delivery! In which case, the obstetrician may opt for a caesarean, after you have explained the advantages and disadvantages, of course.
In case of complete seat, the baby is in a suit, the buttocks resting on the bottom of the uterus, feet also at this level. Same thing: doctors can try an external version and opt for a caesarean section if the baby does not change position.
What is the transverse position?
Even rarer than the seat or the rear position, the transverse position (less than 1% of babies)! This time your baby is lying across the uterus, as in a hammock, legs on one side, the head of the other. The obstetrician may attempt a "external version" (see above), but sometimes, again, that your baby does make his own way and is repositioning itself through! Caesarean section is needed.