Associations of excess weight gain during pregnancy with long-term maternal overweight and obesity: evidence from 21 y postpartum follow-up

BACKGROUND: The contribution of gestational weight gain (GWG) to the development of obesity may have important implications for mothers in their later lives. However, whether GWG is a strong predictor of body mass index (BMI) 2 decades after the index pregnancy is unknown. OBJECTIVE: We examined the long-term effect of GWG by using a community-based birth cohort study. DESIGN: We followed a subsample of 2055 women from an original cohort of 7223 women who gave birth in Brisbane, Australia, between 1981 and 1983. Multivariable regression and multinomial regression were used to examine the independent associations of GWG per gestational week and Institute of Medicine (IOM) categories of combined prepregnancy BMI and GWG with BMI and its categories 21 y after the index pregnancy. RESULTS: In analyses using GWG per week as a continuous exposure variable, maternal BMI (in kg/m²) increased, on average, by 0.52 (95% CI: 0.31, 0.73) for a 0.1-kg/wk greater GWG. This association became stronger when adjusted for maternal prepregnancy BMI. Analyses with IOM categories showed a greater postnatal increase in BMI for women defined as having excessive GWG (3.72, on average; 95% CI: 3.12, 4.31) than for women with adequate GWG. The women who gained excess weight during pregnancy had increased odds of being overweight [odds ratio (OR): 2.15; 95% CI: 1.64, 2.82] or obese (OR: 4.49; 95% CI; 3.42, 5.89) 21 y after the index pregnancy. These associations were independent of other potential factors. CONCLUSION: Weight gain during pregnancy independently predicts the long-term weight gain and obesity of women.