New limit advised for weight gain during pregnancy

Brendan Doyle | McClatchy Newspapers

WASHINGTON — Telling a pregnant woman to eat for two is bad advice, especially if the mother-to-be is overweight or obese, a blue-ribbon panel of health experts cautioned Thursday.

The number of seriously overweight women of child-bearing age is increasing, panelists said, and excessive weight gain leads to an increased likelihood of cesarean sections and retaining the weight added during pregnancy. It also increases the risk of premature, underweight or overweight babies.

To address those problems, the group recommends that obese women, when they're pregnant, gain no more than 20 pounds unless consultation with their physicians produces another target. Until now, there'd been no upper limit on weight gains for obese pregnant women in the influential Institute of Medicine guidelines on weight and pregnancy, since they were such a small part of the population.

A group of physicians, nutritionists and public health doctors assembled by the institute and the National Research Council devised the new recommendation. The institute's recommendations are the basis for most doctors' guidance on weight and pregnancy. The revision released Thursday is the institute's first update since 1990, and it reflects large increases in obesity.

Obesity and other body-weight categories are determined by a ratio of height to weight called body mass index. To compute yours, and find out whether you're over-, under- or normal weight, go to the National Institutes of Health online calculator at http://www.nhlbisupport.com/bmi/

The average U.S. weight gain today for women during pregnancy is 30.5 pounds, according to the panel's chair, Kathleen M. Rasmussen, a nutritional scientist at Cornell University in Ithaca, N.Y.

The recommended weight-gain ranges in pregnancy are:

For underweight women: 28-40 pounds.

For normal-weight women: 25-35 pounds.

For overweight women: 15-25 pounds.

For obese women: 11-20 pounds.

"This is a pretty robust set of recommendations," Rasmussen said. "We have ample evidence that woman who gain within these guidelines do well."

She and other panelists urged women to consider whether they're at healthy weights before they become pregnant, when possible, and to discuss pregnancy-weight issues with their doctors.

"The mother's weight status affects both the mother and her child," Rasmussen said. "More women need to be in a healthy BMI range before conceiving."

Panelists stressed that patients must take into account their own metabolisms and tendencies to gain weight.

"What has shown glimmers of success was to tailor weight-gain guidelines for the women," said Anna Maria Siega-Riz, a maternal- and child-health scientist at the University of North Carolina, Chapel Hill. "What happens frequently is women are given the guidelines without thought to their preference or personal needs."