Long-term risk of offspring type 1 and type 2 diabetes following maternal gestational diabetes mellitus: a nationwide birth cohort study with 10-year follow-up.

Abstract

Evidence on the individual risks of type 1 and type 2 diabetes following gestational diabetes mellitus (GDM) exposure, particularly in large Asian populations, remains limited. We examined whether maternal GDM increases the risk of type 1 and type 2 diabetes in offspring in a Korean nationwide cohort. After excluding mothers with preexisting diabetes, we analyzed a nationwide Korean birth cohort of 3,491,680 mother-child pairs from 2009 to 2018, followed for up to 14 years. Type 1 diabetes was defined as International Classification of Diseases, 10th Revision (ICD-10) E10 with insulin prescription; type 2 diabetes as ICD-10 E11-E14 with antidiabetic medication use. Cox proportional hazards models were used to estimate hazard ratios (HRs) across three groups, offspring born to mothers without GDM (reference), with GDM but not treated with insulin, and with GDM treated with insulin, adjusting for maternal and neonatal covariates. Of the total cohort, 424,185 (12.1%) pregnancies were complicated by GDM, among which 30,003 (7.1%) required insulin therapy during pregnancy. GDM without insulin therapy was not associated with type 1 diabetes in offspring (HR, 0.857 [95% confidence interval, 0.696-1.054]). However, offspring of GDM mothers requiring insulin during pregnancy had a higher risk of type 1 diabetes (HR, 1.936 [1.228-3.052]). For offspring type 2 diabetes, GDM without insulin during pregnancy was significantly associated with increased risk (HR, 1.281 [1.146-1.433]), with a greater risk among insulin-treated GDM pregnancies (HR, 4.329 [3.555-5.270]). Maternal GDM without insulin therapy is associated with an increased risk of type 2 diabetes, but not type 1 diabetes, in offspring, whereas insulin treatment for GDM during pregnancy is associated with increased risk for both type 1 and type 2 diabetes. These findings underscore the need for individualized postnatal monitoring for offspring of mothers with GDM, with heightened attention for those whose mothers required insulin therapy during pregnancy.