Randomized Trial of a Behavioral Intervention to Prevent Excessive Gestational Weight Gain: The Fit for Delivery Study

Abstract

Women with excessive weight gain during pregnancy are at risk for high postpartum weight retention and long-term obesity. The National Academy of Science Institute of Medicine (IOM) issued guidelines in 1990 on specific ranges for healthy weight gains during pregnancy based on body mass index. The majority of normal-weight (NW) and overweight or obese (OW/OB) women have been shown to exceed the IOM guideline ranges for gestational weight gain. Behavioral intervention has been used effectively to promote weight loss with other populations, but no adequately powered randomized trial has examined the effectiveness of behavioral lifestyle intervention in pregnant NW and OW/OB women to reduce excessive gestational weight gains and postpartum weight retention. This randomized, assessor-blind, controlled trial was designed to determine whether behavioral intervention in NW and OW/OB women during pregnancy would decrease the proportion of women who exceeded the 1990 IOM guidelines for gestational weight gains and increase the proportion of women who returned to pregravid weights by 6 months postpartum. A total of 401 NW and OW/OB women were randomized to receive a behavioral intervention (n = 201) or standard care (n = 200) from the 13.5 weeks of gestation until delivery. The average age of the participants was 28.8 years. Each participant in the intervention group received all aspects of standard care plus a behavioral lifestyle intervention consisting of 1 face-to-face visit at the onset of treatment, weekly automated postcards promoting healthy eating and exercise habits and appropriate weight gain, personalized graphs of weight gains, and supportive phone calls with feedback from the dietitian. More than 80% of the participants in both groups completed the 6-month postpartum assessment. The study was conducted according to intent-to-treat analyses. In comparison with standard care, intervention was associated with a decrease in the percentage of NW women who exceeded IOM recommendations (40.2% vs. 52.1%; P = 0.003), and an increase in the percentages of both NW and OW/OB women who by 6 months had returned to their pregravid weights or less than that (30.7% vs. 18.7%; P = 0.005). These findings indicate that low-intensity behavioral intervention can reduce excessive gestational weight gain in NW pregnant women and prevent postpartum weight retention in NW and OW/OB women.