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Does Obesity Begin in the Womb?

Shinichi Maruyama

When I was pregnant with my first son four years ago, I became a little obsessed with eating healthily and gaining only the recommended amount of weight. Although I’m not normally scale-obsessed, I found myself weighing in at least weekly, and even sought the advice of a nutritionist to keep me on target. In retrospect, I think that I was terrified by cautionary tales of women who had used the “eating for two” excuse rather liberally and were struggling to return to their pre-pregnancy size. As it turns out, their weight gain may have been affecting not just them but their babies.

Recent studies have shown that excessive weight gain during pregnancy can result in larger-than-average babies who are “prenatally programmed to become overweight children,” and more likely to develop heart disease, diabetes, and cancer later in life, according to a recent article in the New York Times.

The article explains that new evidence suggests that genetics is not the main reason that so many babies are born jumbo-size, as was previously thought, but that women are more often overweight before becoming pregnant and that some women gain significantly more weight than is recommended. All of this may mean that we’re now in a “vicious cycle of increasing fatness, with prospective mothers starting out fatter, gaining more weight during pregnancy and giving birth to babies who are destined to become overweight adults.”

The current recommendations (revised in 2009) from the Institute of Medicine, the health arm of the National Academy of Sciences, suggest these parameters for pregnancy weight gain, as determined by a woman’s pre-pregnancy weight:

  • 28-40 pounds for thin women, with a BMI (body mass index) of 18.5 or lower
  • 25-35 pounds for normal-weight women, with a BMI of 18.6 to 24.9
  • 15-25 pounds for overweight women, with a BMI of 25 to 29.9
  • 11-20 pounds for obese women, with a BMI of 30 or higher

Moms, were you overweight when you became pregnant? How much weight did your doctor or midwife suggest you should gain? How much weight did you actually gain? How big was your baby?