Your baby's head is the largest part of her body, so when a baby delivers head-first, it usually goes without saying that the rest of the baby follows. But there are many variations from this standard head-first position, such as breech presentation, transverse lie, and shoulder-first. And even if your baby presents head-first, her face can be pointing down, up, or even face-first. These little surprises keep obstetricians and midwives on alert with each seemingly routine delivery.
So what do these various positions mean to you? Here's a primer on baby presentation basics.
In the head-first category, the shape of the mother's pelvis can determine which way the head is placed. The most common way is face-down, allowing the easiest measurement to clear the pelvis. This position is especially helpful because the head can pivot up against the pubic bone, allowing the chin's appearance to finish the delivery of the full head.
Face-up or occipital posterior (back of the head down) is a more difficult delivery because the baby can't flex the head on exit. It's like delivering a baby that weights a full pound more. It's not impossible, but it's more difficult to effectively push, and the pushing stage of labor can last longer than usual.
If your baby's head is sideways, this is called transverse position. Usually the head can be gently rotated by the obstetrician to face-down for a normal delivery.
Asynclitism, or a head-first position wherein the head is tilted to the right or left from the midline, is yet another birth presentation. Many people feel that an epidural given before the head has descended well into the pelvis causes the maternal muscles that normally guide the head down correctly to become relaxed, resulting in a sloppy, unguided descent. It's a hard positioning to work with and can lead to a C-section.