Group intervention in obese women can curb pregnancy weight gain

A behavioral program that includes group meetings can help reduce pregnancy weight gain in obese women and the prevalence of large-for-gestational-age (LGA) infants, according to the results of a study supported by the National Institute of Child Health and Human Development. The findings, from a randomized clinical trial (RCT), were published in Obesity.

Researchers from Kaiser Permanente, Northwest, enrolled 114 obese women (BMI [mean±SD] 36.7 ±4.9 kg/m² at 7 to 21 weeks’ gestation to intervention (n=56) or usual care control conditions (n=58). The intervention consisted of diet and exercise recommendations and behavioral self-management techniques. In contrast, the “usual care” group had a single session with a study dietician during which general information was offered about a healthy diet during pregnancy.

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Diet information offered to the intervention group consisted of individualized calorie goals, advice to keep their weight within 3% of what it was at the start of the study, and to follow a DASH (Dietary Approaches to Stop Hypertension) diet without sodium restriction. At least 30 minutes per day of moderate physical activity also was suggested and the women were encouraged to attend weekly 90-minute group sessions throughout pregnancy on nutrition and/or exercise, behavior change, and goal-setting for the next week.

The main study outcomes were maternal weight change from randomization to 2 weeks postpartum and from randomization to 34 weeks postpartum and from randomization to 34 weeks’ gestation, and newborn LGA (birth weight >90^th percentile, LGA).

From randomization to 34 weeks’ gestation, intervention participants gained less weight (5.0 vs 8.4 kg, mean difference = -3.4 kg, 95% CI [-5.1-1.8]) and from randomization to 2 weeks postpartum (-2.5 vs. +1.2 kg, mean difference=-3.8 kg, 95% CI [-5.9-1.7]). They also had a lower proportion of LGA babies (9 vs. 26%, odds ratio=0.28, 95% CI [0.09-0.84]).

The diet, exercise, and group-meeting intervention, the researchers concluded, “produced lower GWG (gestational weight gain) and reduced the likelihood of LGA infants among obese women.” Limitations of their study, they said, were minimal racial and ethnic diversity and inclusion only of insured women with access to routine prenatal care. 

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