Abstract
OBJECTIVE: To determine whether gestational weight gain (GWG) was associated with increased odds of childhood overweight after accounting for pre-pregnancy BMI. METHODS: In a prospective cohort study based on a premarital and perinatal health care system in China, data of 100 612 mother-child pairs were obtained. The main exposure was GWG as both a continuous and categorical variable. The outcome measure was overweight, defined by age- and sex-specific cutoff values for body mass index (BMI) in children aged 3-6 years. RESULTS: A 1-kg increase in maternal GWG was associated with an increase of 0.009 (95% confidence interval [CI]: 0.007-0.010, P < 0.001) in children's mean BMI; in the subgroup of pre-pregnancy overweight/obese mothers, the increase in children's BMI was 0.028 (95% CI, 0.017-0.039, P < 0.001). Excessive GWG played an important role in childhood overweight when adequate GWG was used as the reference, with an odds ratio (OR) of 1.21 (95% CI, 1.12-1.29). The risk was highest (OR 2.22; 95% CI, 1.79-2.76) in the children of mothers who were overweight/obese before pregnancy and gained excessive weight during pregnancy. CONCLUSIONS: Greater maternal GWG was associated with greater offspring BMI, and the risk of overweight was doubled in children whose mothers were overweight/obese before pregnancy and gained excessive weight during pregnancy. As a result, maintenance of appropriate weight gain during pregnancy and prophylaxis of maternal overweight/obesity before pregnancy should be a strategy for preventing childhood overweight/obesity.