Friday, March 02, 2007


Take a look at these quotes and impressions shared with reporters by Marian MacDorman, the lead author of the paper published in September 2006:
What might explain the increased death rate among C-section babies? MacDorman speculates that the benefits of vaginal delivery might play more of a role than any risks of the surgery itself.(US News)

"The point of this article is not to alarm anyone. Women considering an elective Caesarean obviously should consult with their doctor, and this would be one piece of information that hopefully they could discuss."

She added: "These findings should be of concern for clinicians and policy-makers, who are observing the rapid growth in the number of primary Caesareans to mothers without a medical indication." (The Scotsman)
Malloy, a co-author of the study, offered this quote to the New York Times:
“Despite attempts to control for a number of factors that might have accounted for a greater risk in mortality associated with C-sections, we continued to observe enough risk to prompt concern," he said.

"When obstetricians review this information, perhaps it will promote greater discussion within the obstetrical community about the pros and cons of offering C-sections for convenience and promote more research into understanding why this increased risk persists."
Articles in the popular lay publications included titles such as:
3X More Babies Die After Elective C-Section (MSNBC)
Cesarean on the Rise Despite Risks to Baby, Mom (Fox News)
Voluntary C-Sections Result in More Baby Deaths (New York Times)
Based on these dramatic quotes and the headlines that they generated, you would think that the authors were sure that the evidence showed that elective C-sections increased the risk of neonatal mortality. But you would be wrong. That's because, as the authors were aware, the birth certificate data on which they based their study is notoriously unreliable for listing all complications. The authors never examined maternal request C-sections. They only looked at C-sections that failed to list a complication on the birth certificate, and implied that these C-sections were done without any medical indication.

As I referenced two papers in discussing the article with Henci Goer:
How Well Do Birth Certificates Describe the Pregnancies They Report? The Washington State Experience with Low-Risk Pregnancies, Dobie, Baldwin, et al., Maternal Child Health Journal, 2:3, September 1998.

Conclusions: Because birth certificates significantly underestimated the complications of pregnancies, number of interventions, number of procedures, and prenatal visits, use of these data for health policy development or resource allocation should be tempered with caution.

The reporting of pre-existing maternal medical conditions and complications of pregnancy on birth certificates and in hospital discharge data, American Journal of Obstetrics and Gynecology, Volume 193, Issue 1, 125-134, July 2005, M. Lydon-Rochelle, V. Holt, et al. Results Birth certificate and hospital discharge data combined had substantially higher true-positive fractions than did birth certificate data alone for cardiac disease (54% vs 29%), acute or chronic lung disease (24% vs 10%), gestational diabetes mellitus (93% vs 64%), established diabetes mellitus (97% vs 52%), active genital herpes (77% vs 38%), chronic hypertension (70% vs 47%), pregnancy-induced hypertension (74% vs 49%), renal disease (13% vs 2%), and placenta previa (70% vs 33%)... Conclusion In Washington, most medical conditions and complications of pregnancy that affect mothers are substantially underreported on birth certificates,...

Look at the results of this study. For virtually every serious pregnancy complication, more than half the cases appeared on the birth certificate as having no risk factors. It seems pretty clear that there is a serious problem with relying on birth certificate data to determine pregnancy complications..."
I was not the only one to notice this serious problem. In the current issue of Birth, MacDorman et al. respond to this exact issue which was raised in letters to the editor:
We acknowledged the fact that, although we excluded infants with medical risks and complications to the maximum extent possible, it was still possible that some infants with medical risks remained in the study. This fact was why we were careful to use the terminology "no indicated risk" throughout the study. In particular, we never ... referred to the study population as representing "elective" or "cesarean delivery on maternal request". (my emphasis)
In other words, although MacDorman et al. implied that "no indicated risk" accurately represented purely elective C-sections, and although they gave interviews implying the same to the general public, and although they were aware that news organizations were publishing articles that claimed that "no indicated risk" was the same as purely elective, they don't think they should be held accountable. Why? Because the never said explicitly that they were the same and "we were careful to use the terminology 'no indicated risk".

MacDorman et al. made no attempt to determine if the birth certificates they reviewed were accurate. They made no attempt to ascertain if the neonatal deaths they reported were related in any way to the C-section. And they were aware all along that birth certificates leave out 50% of serious complications. So what did they actually show in their study? They showed that C-sections with birth certificates filled out wrong have a higher neonatal death rate than vaginal deliveries!


0 Old Comments: