Pregnancy and new motherhood is one of the most stressful and anxious times for most women as they worry for themselves and the innocent lives in their care. This concern means they’re especially vulnerable to becoming alarmed by health scares and to react out of fear, with potentially harmful outcomes. So it is especially imperative that the health information they receive is well-grounded, credible and helpful.

When the headlining story — which appeared virtually verbatim in media across our country and around the world — told women they were putting their pregnancies and unborn babies at risk if they didn’t lose all of their pregnancy weight and begin their next pregnancies at “healthy” weights; weight loss admonitions began instantly. In fact, the researchers whose study this news story was based upon told media that their “striking findings” provided “the evidence that overweight or obese women who plan to become pregnant should lose weight.”

Even a modest increase of 7 pounds, the public was told, could raise a woman’s risk for pregnancy-related complications, such as gestational diabetes by 30% and pregnancy hypertension 40%. But they delivered even more frightening news, warning women that “gaining 3 or more units of BMI (body mass index) raises the risk of a stillbirth by 63%, pre-eclampsia and gestational hypertension by 78% and 76%, and could double her risks for gestational diabetes.”

“These are staggering numbers,” Daniel Herron was quoted as saying. Women should not wait for later research before changing their behavior and losing weight between pregnancies, he added. [Not a single reporter revealed that Herron is not simply an “associate professor of surgery at Mount Sinai Hospital ” as they reported. He is Chief of Bariatric Surgery with Mount Sinai ’s Program for Surgical Weight Loss, as well as on the Public/Professional Education Committee of the American Society for Bariatric Surgery. Readily-known interests, in promoting fears of obesity and the need for weight loss, the media didn’t disclose.]

Also quoted in the media reports was a reproductive health specialist with the World Health Organization who said: “This is the first study to provide...the necessary evidence to show a causal relationship between obesity and adverse outcomes.”

What is passing for evidence and sound interpretations by health authorities is, in fact, what is most staggering.

What did the study show?

This study was conducted by Eduardo Villamor, M.D., of Harvard School of Public Health and Sven Cnattingius, M.D., of the Karolinska Institute in Stockholm. They sorted through data from the medical records of 151,025 Swedish women who had had their first and second babies during 1992-2001. It was a “ case-controlled ” study, looking retrospectively through histories trying to find correlations between BMIs and pregnancy complications. The researchers applied statistical modeling of the data to create the odds ratios they reported.

To make any sense of their findings, we must first understand what an odds ratio actually means. See side bar: Odds Ratios .

