Efficacy of a group-based dietary intervention for limiting gestational weight gain among obese women: a randomized trial

OBJECTIVE: Observational studies suggest that minimal gestational weight gain (GWG) may optimize pregnancy outcomes for obese women. This trial tested the efficacy of a group-based weight management intervention for limiting GWG among obese women. METHODS: We randomized 114 obese women (BMI [mean±SD] 36.7±4.9 kg/m(2)) between 7–21 weeks’ (14.9±2.6) gestation to intervention (n=56) or usual care control conditions (n=58). The intervention included individualized calorie goals, advice to maintain weight within 3% of randomization and follow the Dietary Approaches to Stop Hypertension dietary pattern without sodium restriction, and attendance at weekly group meetings until delivery. Control participants received one-time dietary advice. Our three main outcomes were maternal weight change from randomization to 2 weeks postpartum and from randomization to 34 weeks gestation, and newborn large-for-gestational age (birth weight >90(th) percentile, LGA). RESULTS: Intervention participants gained less weight from randomization to 34 weeks gestation (5.0 vs 8.4 kg, mean difference=−3.4 kg, 95% CI [−5.1, −1.8]), and from randomization to 2 weeks postpartum (−2.6 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]). CONCLUSIONS: The intervention resulted in lower GWG and lower prevalence of LGA newborns.