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.