Supervised exercise-based intervention to prevent excessive gestational weight gain: a randomized controlled trial.

Objective: To study the effect on maternal weight gain of a supervised light- to moderate-intensity exercise-based intervention performed from the ninth week of pregnancy.

Participants And Methods: A total of 962 healthy pregnant women were randomly assigned to a standard care or exercise intervention group conducted between September 1, 2007, and January 31, 2011. The intervention included light- to moderate-intensity aerobic and resistance exercises performed 3 days a week (50-55 minutes per session). Excessive gestational weight gain was calculated on the basis of the 2009 Institute of Medicine (IOM) recommendations. Gestational body weight gain was calculated on the basis of the weight measured at the first prenatal visit (fifth to sixth weeks of gestation) and weight measured at the last visit to the clinic before delivery. Women were categorized into normal weight or overweight or obese.

Results: Women in the intervention group gained less weight (adjusted mean difference, 1.039 kg; 95% CI, 0.534-1.545 kg; P<.001) and were less likely to gain weight above the IOM recommendations (odds ratio, 0.625; 95% CI, 0.461-0.847) compared with those in the standard care group. The main treatment effects according to body mass index category were that normal weight women in the intervention group gained less weight (adjusted mean difference, 1.393 kg; 95% CI, 0.813-1.972 kg; P<.001) and were less likely to gain weight above the IOM recommendations (odds ratio, 0.508; 95% CI, 0.334-0.774) than normal weight women who received standard care. No significant treatment effect was observed in overweight or obese women.

Conclusion: Supervised exercise of light to moderate intensity can be used to prevent excessive gestational weight gain, especially in normal weight women.

Trial Registration: clinicaltrials.gov Identifier: NCT01790347.