36-week checkup

(actually, just shy of 37 weeks) And I'm about 30% effaced! There's no dilation yet, but since I'm a first-timer, that's not really expected until I go into labor. It's exciting to know that my body is gearing up to do this - and that I really won't be pregnant much longer!

The Honeymoon is Over?

As if my baby shower marked the point after which the ease and fun of pregnancy ended, I woke up the next few days after the shower with sore feet, a sore right wrist, and tingly fingers. My feet, fortunately, have since recovered (I think I had simply been standing too often throughout the weekend) - yay! But I still have the mild carpal tunnel symptoms that sometimes manifest once late pregnancy maxes out the mother's circulatory system. It's no fun, and it's slowing down my thank-you note writing, but compared to some pregnancy tales of woe and misery I've heard, it's no big deal either.

More on the awesome baby shower my girls threw for me in my next post!

More on Natural Childbirth

We went to our second (of six) birthing classes this week. The class is taught by a very experienced doula who is generally pro-natural-childbirth, and one of the things she explained to us this week is how the usual process of birth causes the baby to corkscrew through the mother's pelvis. Because the pelvis is widest from side to side at the top, and the baby's head is widest from front to back, the baby's head typically enters the pelvis facing sideways. However, by the bottom, the pelvis is widest from front to back, and so the baby generally turns to face backwards as it descends, finally turning to the side again as the shoulders present. (See page 179 of the Mayo Clinic Guide to a Healthy Pregnancy for a diagram and description of this characteristic movement.)

What effects this complex maneuver as the baby descends?

According to our instructor, tension and relaxation of the pelvic floor muscles is part of what causes the turning as the baby descends, pushed down by uterine contractions. This is one reason that she thinks it is often best to avoid an epidural, as these voluntary muscles stay uniformly relaxed throughout labor when anesthetized, which apparently makes the proper corkscrew descent more difficult.

This makes some sense on the face of it, but unfortunately, I have been unable to find any hard information to confirm or contradict this claim. While most texts on labor I have read describe this typical pattern of descent, none of them are clear on what causes it. (Most just describe how "the baby turns", though it obviously isn't choosing its path as it descends!) Space limitations must play some role in turning the baby, but I am curious as to whether anything about the actions of the involuntary muscles (the uterus) or the voluntary muscles (pelvic floor muscles) changes during different parts of labor to help this turning. If what our instructor has said is correct, this would be a good reason to avoid an epidural if possible. It would also help explain why the process of birth tends to slow or stall with an epidural. Readers: if any of you have more information on this claim, either in support of or against it, please post it to the comments!