Excess pregnancy weight gain and long-term obesity: one decade later.

OBJECTIVE To estimate the impact of excess pregnancy weight gain and failure to lose weight by 6 months postpartum on excess weight 8-10 years later. METHODS Seven hundred ninety-five women were observed through pregnancy and 6 months postpartum to examine factors that affect weight loss. Weight was recorded 10 years later through a medical record review to examine the impact of retained weight on long-term obesity. Overall weight change at last follow-up and body mass index (BMI) were examined by pregnancy weight gain appropriateness according to the Institute of Medicine guidelines for weight gain during pregnancy. RESULTS Of the original cohort, 540 women had a documented weight beyond 5 years (mean = 8.5 years). The average weight gain from prepregnancy to follow-up was 6.3 kg. There was no difference in weight gain by prepregnancy BMI. Women who gained less than the recommended amount during their pregnancy were 4.1 kg heavier at follow-up, those gaining the recommended amount were 6.5 kg heavier, and those gaining more than recommended were 8.4 kg heavier (P =.01). Women who lost all pregnancy weight by 6 months postpartum were 2.4 kg heavier at follow-up than women with retained weight, who weighed 8.3 kg more at follow-up (P =.01). Women who breast-fed and women who participated in aerobic exercise also had significantly lower weight gains. CONCLUSION Excess weight gain and failure to lose weight after pregnancy are important and identifiable predictors of long-term obesity. Breast-feeding and exercise may be beneficial to control long-term weight.