The recommendations call for a gestational weight gain of 28-40 pounds for underweight women, 25-35 pounds for women of normal weight, 15-25 pounds for overweight women and 11-20 pounds for obese women. The only change is for obese women, who were previously advised to gain at least 15 pounds, with no upper limit.
The problem is not the guidelines, but the failure to adhere to them and to address obesity in reproductive-age women, said Dr. Maxine Hayes, state health officer for the Washington State Department of Health and chairwoman of a 2006 panel that urged a reexamination of the guidelines. "If we wait for every woman to be advised about weight gain after they become pregnant, it's too late. It puts women and their babies on a trajectory that is unhealthy."
During the two-year process of reexamining the guidelines, committee members tried to balance the health needs of the fetus with the health needs of the mother, Rasmussen said, ultimately deciding that the recommendations were largely up-to-date already.
Not all experts in maternal-fetal health are convinced.
"We have been doing this same recommendation for 19 years, and it has been very unsuccessful," said Susan Y. Chu, a senior epidemiologist at the Centers for Disease Control and Prevention who has studied gestational weight gain. "But they did what was most critical, which was to put a cap on the obese category."
Several studies suggest that obese women may require little weight gain as long as it's clear that the fetus is growing.
"We have determined that overweight and obese women can benefit and have better pregnancy outcomes if they limit their weight gain," said Artal, the author of several studies on obese pregnant women. "The committee was cautious. They were concerned they might cause harm. But by maintaining the status quo, I think that may cause more harm."
A study in the June issue of the Journal of the National Medical Assn. found that obese pregnant women who followed well-balanced diets and gained little or no weight had better outcomes -- as did their babies -- than women who gained more weight.
That study's lead author, Dr. Yvonne S. Thornton, a professor of obstetrics and gynecology at New York Medical College, said the committee may have feared an increase in births of underweight infants if more pregnant women were placed on restricted diets. "This is a litigious society," she said. "If we did restrict calories and there was an untoward outcome, people might say, 'Well, you didn't feed me enough.' "
