Obesity Causes a Rise in… Articles about the Cesarean Rate

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By Jill

If the cesarean rate goes down to the mid-20’s over the next ten years, who will be the first to offer up their expert opinion to the press and inspire titles like “Cesarean Rate Down, Fewer U.S. Women May Be Obese” in newspapers?

The problem with many articles in which an expert attributes the high cesarean rate to rising obesity rates is that they are written with an obvious anchoring bias that these cesareans were all necessary (due to a complication of obesity) because they were performed and that they would not been performed had they not been necessary. It’s the argumentum ad necesarean.

Except for the article in the New York Times in June 2010 which said something original about a consortium’s plans to build a separate hospital for obese pregnant women, most articles about obesity and cesareans tell the reader nothing more than doctors are more likely to perform a cesarean on obese women.

Saying that doctors are more likely to perform a cesarean on an obese women tells readers that doctors are more likely to perform a cesarean on an obese women. Period.

My point is not that obesity has no effect on the likelihood that a cesarean will be needed to prevent injury or death to mother or baby. My point is that the majority of articles written trying to link the rise in obesity to the rise in the cesarean rate tell us nothing more than an article linking the rise in the cesarean rate to the rise in housing prices.

The Well-Rounded Mama wrote about some of the actual risks associated with obesity and pregnancy in her post, Exaggerating the Risks Again:

For example, Weiss (AJOG, 2004), a large study of more than 16,000 women in multiple hospital centers, found that 9.5% of “morbidly obese” women (BMI more than 35) experienced Gestational Diabetes during their study.  The number certainly is higher than the 2.3% with a BMI less than 30, so it is definitely a risk (4x the risk—-gasp!) that should be communicated to women of size.  

However, it also means that 90% of “morbidly obese” women did not develop Gestational Diabetes.  So while the risk increased, it should be remembered that the vast majority of morbidly obese women will not get GD.  

Pre-eclampsia is another risk that is substantially increased in “obese” women, and this one can be life-threatening to both mother and baby.  It is definitely a risk that must be discussed as a possibility and taken very seriously.  But in the Weiss study, only 6.3% of “morbidly obese” women developed Pre-eclampsia….higher than the 2.1% of non-obese women (3.3x the risk—-gasp!) who developed PE, but hardly universal.  Remember, 93% of “morbidly obese” women did not develop Pre-eclampsia in that study.  

Again, the majority of these women did not get GD or PE, the two most common risks for women of size.

So while these risks are real and it’s only sensible that the possibility be discussed with women of size (and that women of size be proactive about lessening their risk for them), it’s important that the magnitude of the risks not be exaggerated or to imply that such a complication is virtually inevitable. 

If you’re a journalist and you’re going to interview an expert on the correlation between obesity and cesarean sections, don’t just settle for something like, “I perform more cesareans on obese patients; therefore, I deem them to be necessary.” Please get percentages and citations. If they don’t want to or can’t give you any numbers, that’s your story.