Association between Prepregnancy Weight Change and Risk of Gestational Diabetes Mellitus in Chinese Pregnant Women

Background: Evidence regarding prepregnancy weight change and gestational diabetes mellitus (GDM) is lacking among East Asian women. Objectives: Our study aimed to investigate the association between weight change from age 18 y to pregnancy and GDM in Chinese pregnant women. Methods: Our analyses included 6972 pregnant women from the Tongji-Shuangliu Birth Cohort. Body weights were recalled for age 18 y and the time point immediately before pregnancy, whereas height was measured during early pregnancy. Prepregnancy weight change was calculated as the difference between weight immediately before pregnancy and weight at age 18 y. GDM outcomes were ascertained by 75-g oral-glucose-tolerance test. Multi-variable logistic regression models were used to examine the association between prepregnancy weight change and risk of GDM. Results: In total, 501 (7.2%) developed GDM in the cohort. After multivariable adjustments, prepregnancy weight change was linearly associated with a higher risk of GDM (P < 0.001). Compared with participants with stable weight (weight change within 5.0 kg) before pregnancy, multivariable-adjusted odds ratios and 95% confidence intervals were 1.55 (1.22, 1.98) and 2.24 (1.78, 2.83) for participants with moderate (5-9.9 kg) and high (& GE;10 kg) weight gain, respectively. In addition, overweight/obesity immediately before pregnancy mediated 17.6% and 31.7% of the associations of moderate and high-weight gain with GDM risk, whereas weekly weight gain during pregnancy mediated 21.1% and 22.7% of the associations. Conclusions: Weight gain from age 18 y to pregnancy was significantly associated with a higher risk of GDM. Maintaining weight stability, especially prevention of excessive weight gain from early adulthood to pregnancy, could be a potential strategy to reduce GDM risk.