Ask an OB: What does that mean?

"Ask an OB" is a weekly series with Dr. Maude "Molly" Guerin, MC, FACOG. If you have a question for her, please share it with us here. 

I've heard people talk about pushing against a "cervical lip" during labor. What does this mean? Why does it happen? Are there any risks involved? - East Lansing Mom

“Cervical lip” refers to the nub of cervix that is left when the cervix is almost fully dilated. When the cervix is fully dilated it disappears and all you can feel is the baby’s head, with no little “cuff” of cervix around it. When the cervix is ALMOST fully dilated you can feel a little edge of cervix, usually right under the pubic bone, that puffs up because of the pressure of the baby coming down. Eventually this lip usually disappears, and then you can push. If the pelvis is too small this little “lip” never does go back around the head – so you never get fully dilated. If you start pushing before the lip is gone (in other words before you are fully dilated) one of 3 things will happen: 1) you will tear the cervix, deliver, but maybe have a weak cervix next time leading to premature delivery. 2) the lip will not go back, will swell up, and you will never deliver vaginally 3) the lip will go back over the head and all will be well. Pushing against a lip for a short time might be OK to see if it goes back easily, but if it doesn’t do that, you need a hospital.

What is "caput" and what does it indicate for a laboring mother/baby? - East Lansing Mom

Caput refers to the swelling that occurs on the top of the baby’s head in response to coming through the pelvis. The pelvic sidewalls form a tight “chute” and the baby helps fit through by “molding” the skull bones to make the head literally more pointy. The leading portion of the scalp gets swollen from all the pressure, and gives baby the “cone head” so characteristic of first labors (and completely normal). With subsequent labors, the baby spends very little time deep in the pelvis – some second babies come shooting out in one push!- so the swelling and molding are much less. When more and more caput forms, we worry that the baby is stuck – the bones can’t fit, but the contractions keep trying to force the baby through.

You can read more about Dr. Maude "Molly" Guerin, MD, FACOG, right here.