Fewer New Pounds in Pregnancy Best for Obese Moms

ByABC News
June 2, 2009, 6:02 PM

June 3 -- TUESDAY, June 2 (HealthDay News) -- In a study that reinforces recent changes in pregnancy weight gain recommendations, obese women who gained little or no weight while pregnant had better outcomes than obese women who gained more.

Just last week, experts at the U.S. Institute of Medicine and the National Research Council updated their gestational weight gain guidelines to urge that obese women gain only 11 to 20 pounds during pregnancy -- down from a minimum weight gain of 15 pounds that had been recommended in 1990.

In the new study, published in the June issue of the Journal of the National Medical Association, researchers divided 232 obese women, all with a body mass index greater than 30, into two groups. One group was given standard advice: to "eat to appetite." The other group was given nutritional counseling, told to keep a food diary and placed on a diet that limited calories to between 2,000 and 3,500 a day, depending on their pre-pregnancy weight.

By the end of the pregnancy, the average weight gain in the group of women who stuck to their normal diets was 31 pounds. The average weight gain for women in the calorie-restriction group was 11 pounds. Twenty-three extremely obese women actually lost weight during their pregnancy.

The results seem to support less, not more, weight gain during pregnancy. Women in the calorie-restricted group had fewer C-sections and lower rates of gestational diabetes and hypertension and had retained less weight six weeks after delivery.

Fewer women in the calorie-restricted group delivered newborns weighing more than 10 pounds, which can make deliveries risky for both mother and child. There were no growth-restricted babies in either group.

"Women who are obese when beginning a pregnancy are, by definition, unhealthy," noted Dr. Yvonne Thornton, a clinical professor of obstetrics and gynecology at New York Medical College and the study's lead author. "To say that they should gain even more weight is counterintuitive, and our study bears that out."