Association between gestational weight gain and risk of overweight at 3 years old: The Japan Environment and Children's Study.

Background: It is unclear if gestational weight gain (GWG) increases the risk of children with overweight.

Objectives: We examined the association between GWG and the risk of overweight in 3-year-old children in the Japanese nationwide birth cohort study.

Methods: Among 64 336 singleton births, we calculated the risk ratios (RRs) and 95% confidence intervals (95% CIs) of the association between GWG categories and children with overweight, following an adjustment of the confounding variables.

Results: GWG was positively associated with the risk of overweight among 3-year-old children. The multivariable RR (95% CI) was 1.21 (1.17-1.25) per 5 kg increase of the GWG. The multivariable RR (95% CI) for excessive GWG was 1.20 (1.12-1.28) and 1.27 (1.16-1.39) based on the modified Japanese and IOM criteria, respectively, compared to adequate GWG. The multivariable RR (95% CI) of overweight with children for inadequate versus adequate GWG was 0.83 (0.78-0.88) and 0.84 (0.79-0.89) based on the modified Japanese and IOM criteria, respectively.

Conclusions: GWG was positively associated with a high risk of overweight at 3 years of age. The risk of offspring overweight was 20%-27% higher and 16%-17% lower with excessive GWG and inadequate GWG, respectively, compared to adequate GWG, based on the aforementioned criteria.