Association of trajectories of healthy lifestyle during pregnancy and gestational diabetes mellitus and the mediation of gestational weight gain: a multicenter cohort study in China

Background: This study aimed to explore associations between trajectories of combined healthy lifestyle scores from first to second trimester and the risk of GDM and to explore the potential mediation effects of eGWG. Methods: 7732 pregnant women were included in 24 hospitals from 15 provinces in China from 2017 and followed up to 2018. Healthy lifestyle behaviors included non-smoking, non-alcoholic drink, consuming a healthy diet, exercising regularly, having a low stress level and good sleep. Association between healthy lifestyle scores, eGWG and GDM were with and group-based trajectory modelling (GBTM), logistic regression and mediation analysis. Results: GBTM identified five trajectories: compared with persistently low-stable trajectory of healthy lifestyle scores, women with moderate-stable (OR = 0.68, 95% CI: 0.56-0.80), high-falling (OR = 0.60, 95% CI: 0.41-0.79), low-rising (OR = 0.59, 95% CI: 0.40-0.73), and high-stable trajectory (OR = 0.56, 95% CI: 0.44-0.68) had a decreased risk of GDM; 14.02% (95% CI: 5.32%-56.24%), 16.11% (95% CI: 3.13%-60.54%), 13.71% (95% CI: 4.38%-58.95%) and 7.13% (95% CI: 1.83%-32.53%) of the associations, respectively, were mediated by eGWG. Conclusion: Adherence to multiple healthy lifestyle behaviors from first to second trimester was associated with low risk of GDM, and it was partially mediated by eGWG.