Cephalopelvic Disproportion (CPD)
Worried baby will be too big for a vaginal birth. We've got the details on just how common CPD is -- and how to know if you've got it. Plus, everything you want to know if you do.
What is cephalopelvic disproportion (CPD)?
Don’t let the medical speak intimidate you: Cephalo (head) pelvic (pelvis) disproportion (one’s too big for the other) is just Latin for “there’s no way the baby’s going to fit down there” for delivery. Doctors also use this as a general term for a lack of progress in labor (your cervix isn’t dilating, or the head isn’t descending).
Are there any tests for CPD?
A good old-fashioned physical exam measuring the size of your pelvis and also an ultrasound can help estimate your baby’s size before you go into labor, but neither is 100 percent accurate. In the end, it’s difficult to predict the condition before labor starts, since your body can change in some amazing ways once the birthing process begins. Plus, there’s no good way to know how the head and pelvis will actually match up. (Don’t worry -- if your baby is very large, say, over 10.5 pounds, your doctor may order a c-section anyhow.)
How common is CPD?
It’s rare. True CPD occurs in about 1 out of 250 pregnancies and requires cesarean delivery. Luckily, even if you’ve been diagnosed with CPD, that doesn’t mean all your future deliveries will be under the knife: Research shows more than 65 percent of women who had CPD in a previous pregnancy were able to have a vaginal delivery the next time around.
How did I get CPD?
It might just be biology. Maybe you just happen to have a somewhat narrow or small pelvis and your baby has a larger-than-average-size head.
How will CPD affect my baby?
Most likely, she’ll simply be delivered via c-section. There’s no evidence to indicate that CPD will affect your baby in any other way after birth.
Next page: Prevention, treatments and more resources for CPD