For women with
gestational diabetes mellitus (GDM), the evaluation of
glucose tolerance (GT) in the early postpartum period is universally recommended. Nevertheless, few studies have evaluated the risk factors for T2DM on the basis of GT data obtained during the early postpartum period. We aimed to identify the risk factors for
type 2 diabetes mellitus (T2DM) by evaluating GT in the first 12 weeks postpartum (12wPP) in women with GDM and to categorize the risk using a combination of the principal risk factors. This retrospective multicenter observational study included 399 East Asian women with GDM who underwent a 75-g oral
glucose tolerance test (OGTT) within 12wPP, which was repeated annually or biennially and used to identify the postpartum development of T2DM. Forty-three women (10.8%) developed T2DM during a median follow-up period of 789 ± 477 days. The independent risk factors for T2DM were pre-pregnancy
obesity (BMI ≥25 kg/m2), early postpartum impairment in
glucose tolerance (IGT), and an early postpartum
glycated hemoglobin (HbA1c) ≥5.7%. The odds ratios (95% confidence intervals) for T2DM were 3.2 (1.3-7.8) in women with either early postpartum IGT or pre-pregnancy
obesity, 9.2 (3.0-28.3) in those with early postpartum IGT, pre-pregnancy
obesity, and HbA1c <5.7%, and 51.4 (16.1-163.9) in those with early postpartum IGT, pre-pregnancy
obesity, and HbA1c ≥5.7%, compared with those without
obesity or IGT. T2DM risk in East Asian women with GDM should be stratified according to pre-pregnancy
obesity and early postpartum IGT, and these patients should be followed up and receive appropriate care for their risk category.