Gestational weight gain trajectories in insulin resistance subtypes of gestational diabetes mellitus and their associations with adverse pregnancy outcomes

Gestational diabetes mellitus (GDM) is closely associated with adverse pregnancy outcomes (APOs) and long-term health risks for both mother and child. Different insulin resistance (IR) subtypes of GDM are characterized by distinct pathogenic mechanisms, which may require individualized clinical management. In this study, we analyzed the gestational weight gain (GWG) in the GDM IR subtypes, aiming to provide a self-monitoring indicator for the tailored management strategy. This retrospective cohort study included 2,694 women with singleton pregnancies who delivered at the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region between May 2019 and December 2021. Participants were stratified into GDM and Non-GDM groups with high IR (HIR), appropriate IR (AIR) and low IR (LIR), respectively. GWG percentile curves were constructed using GAMLSS method. Weight gain across different trimesters was compared, and the associations between GWG and APOs were analyzed using multivariable logistic regression models with false discovery rate correction. Total GWG was significantly lower in women with GDM than in Non-GDM women. In early pregnancy, the GDM_HIR subgroup showed the highest weight gain, while weekly weight gain declined during mid-pregnancy across all GDM subgroups, with the most pronounced changes observed in GDM_HIR. In multivariable analyses, higher total GWG in GDM_HIR was associated with lower odds of LBW (aOR = 0.857, 95% CI: 0.777–0.940, p = 0.001, q = 0.012) and SGA (aOR = 0.848, 95% CI: 0.779–0.919, p < 0.001, q = 0.002), whereas higher third-trimester GWG was associated with an increased risk of LGA (aOR = 1.177, 95% CI: 1.046–1.327, p = 0.007, q = 0.032). In GDM_AIR, higher total GWG was associated with LGA (aOR = 1.177, 95% CI: 1.072–1.299, q = 0.008), and higher third-trimester GWG was associated with preeclampsia (aOR = 1.443, 95% CI: 1.144–1.850, q = 0.012). GDM IR subtypes displayed distinct GWG patterns across gestation. Stage-specific associations between GWG and APOs were observed within the GDM IR subtypes. Monitoring GWG trajectories may provide useful information for individualized weight management and perinatal risk assessment in women with GDM.