The Problem with the CPD Diagnoses

There’s no way that head was fitting through vaginally!

No wonder you needed a c-section, your baby was so big!

Don’t worry honey, it’s not your fault. Your pelvis is just way too small.

The diagnoses for the cesarean?

Cephalopelvic Disproportion (CPD)
1. a condition in which the fetal head is too large to traverse the maternal pelvis. (MediLexicon)

Either the baby is too big, or the woman’s pelvis is too small, or a combination of both, they say. However, CPD seems to be one  of the most common and the most controversial reasons for a c-section. I personally have known many women who were told that their babies couldn’t fit through their pelvis. Many choose to have an elective cesarean afterwards; others go on to birth subsequent (and sometimes larger) babies vaginally.

So, outside of the labor room, what are people (birth advocates and medical journals alike) really saying about CPD?

“Cephalopelvic disproportion (CPD) occurs when a baby’s head or body is too large to fit through the mother’s pelvis. It is believed that true CPD is rare, but many cases of “failure to progress” during labor are given a diagnosis of CPD. When an accurate diagnosis of CPD has been made, the safest type of delivery for mother and baby is a cesarean.” – American Pregnancy Association (APA).

“Cephalopelvic disproportion is rare. According to the American College of Nurse Midwives(ACNM), CPD occurs in 1 out of 250 pregnancies. If you have been diagnosed with CPD, it does not mean that you will have this problem in future deliveries. According to a study published by the American Journal of Public Health, more than 65 % of women who had been diagnosed with CPD in earlier pregnancies, were able to deliver vaginally in subsequent pregnancies.” APA

“When a diagnosis of CPD has been made, many people still believe that this constitutes a reason for elective repeat caesarean section in future pregnancies, despite the wealth of evidence to the contrary. Indeed, there have been many documented cases where women have been diagnosed as having CPD and then gone on to deliver vaginally a larger infant than the one that was delivered surgically.” –Belly Belly

“In one study, 68% of women diagnosed after labor with “absolute CPD” still went on to have a vaginal birth. However, in extremely rare cases, true absolute CPD does exist, usually in the context of severe malnutrition or a permanent injury.” International Cesarean Awareness Network (ICAN) (1).

“A trial of labor is reasonable in women whose previous cesarean was for dystocia in the second stage of labor. In this series, patients who underwent a trial of labor after a previous cesarean for dystocia in the second stage had 75.2% (95% confidence interval 69.5, 81.0) chance of achieving vaginal delivery.Obstetrics & Gynecology (2) (Note that dystocia is associated with a long labor, and is often associated with the CPD diagnoses.)

A woman’s pelvis is flexible and is made to open during birth. When there is interference with the birth process (induction before baby is ready, mother’s movement is restricted, etc.), the pelvis is not able to open to its maximum. The baby’s head molds (changes shape) during labor and delivery in order to fit through the pelvis. Neither the pelvis nor the baby’s head are fixed in one position; both expand and shift as labor progresses. A birthing woman’s pelvis is most likely to expand freely and accommodate the baby when the following conditions are present:

The birth takes place when the baby is ready and when natural birth hormones are present.The laboring woman moves freely to her comfort level.Adequate time is allowed for the molding of the baby’s head.” –ICAN

(All bold print mine.)

All of this is not to say that true CPD doesn’t exist, nor that all cesareans for CPD are bad. But there is sufficient evidence available that should make one rightly question the commonness of the CPD diagnoses. Could it really be that so many women’s bodies are not able to function properly in stretching and opening for a baby? Or that babies are that much bigger today than they were many years ago (say, back in 1970 when we only had a 5% c-section rate?) Or that a women’s pelvises could actually get that much smaller in the past 40 years?

It’s something to think about… and maybe even something worth questioning.

Have you ever been faced with the CPD diagnoses? Do you think it was given rightly? Why or why not?

Check back in next time for a post on how to try to prevent the CPD diagnoses during your birth.

(1) Impey L, O’Herlihy C. First delivery after cesarean delivery for strictly defined cephalopelvic disproportion. Obstet Gynecol 1998 Nov;92(5):799-803.

(2) Bujold, Emmanuel MD; Gauthier, Robert J. MD. Should we allow a Trial of Labor After a Previous Cesarean for Dystocia in the Second Stage of Labor? Obstetrics & Gynecology 2001 Oct; 98(4):652-655.


4 responses to this post.

  1. Posted by Michelle on August 26, 2012 at 10:35 pm

    Wow! The way God created our bodies to adapt during birth is amazing.


  2. […] Read more from the original source: The Problem with the CPD Diagnoses « the birth bug […]


  3. This reminds me of the whole “I couldn’t breastfeed because ______.” The true medical percentage is so slim but then why are so many children being formula-fed? Anyway! I hijacked hit *birth* post! :-p

    Ive always had these hips so I never worried nor was I told to worry about such a thing. Either way, I sort of laugh (inside, to myself) when a pregnant woman says, “oh my doctor said….” and then goes on to lament how she has not other choice but to listen to him.


  4. […] Resources « The Problem with the CPD Diagnoses […]


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