ObjectivesThe gestational weight gain (GWG) and hyperglycemia are two key factors affecting adverse pregnancy outcomes among women with gestational diabetes mellitus (GDM). We aimed to investigate the combinatorial effect of abnormal glucose metabolism and GWG on adverse outcomes in GDM.MethodsThis retrospective cohort study included 2611 pregnant women with GDM in Women’s Hospital School of Medicine Zhejiang University. Bases on the OGTT glucose levels, we categorized the GDM cohort into three subgroups: impaired fasting glucose (IFG) group, impaired glucose tolerance (IGT) group, and combined impaired glucose (IFG&IGT) group.ResultsAmong pregnant women with IGT, insufficient GWG (IGWG) was an independent protective factor for pregnancy-induced hypertension syndrome (PIH) (aOR 0.55, 95% CI 0.32-0.95), macrosomia (0.38, 0.19-0.74) and large for gestational age (0.45, 0.32-0.62), as well as an independent risk factor for low birth weight infants (2.29, 1.24-4.22) and small for gestational age (1.94, 1.17-3.19); and excessive GWG (EGWG) was related to increased risks of PIH (1.68, 1.12-2.52), preterm delivery (1.82, 1.28-2.58), postpartum hemorrhage (1.85, 1.05–3.28), cesarean delivery (1.84, 1.38-2.46) and low body weight infants (2.36, 1.33-4.20). Moreover, EGWG was positively associated with PIH (3.27, 1.09–9.80) in the IFG group. But there were no significant associations between either IGWG or EGWG and any pregnancy outcomes in women with combined IFG&IGT.ConclusionsThe relationships between GWG and adverse outcomes were modified by abnormal glucose metabolism in women with GDM. Our results suggest that more specific GWG recommendations according to their metabolic state are needed for GDM.