Gestational Diabetes Mellitus: Recurrence and Future Type 2 Diabetes Risk Across Racial and Ethnic Groups.

OBJECTIVE: Despite rising diabetes prevalence among women, data on long-term diabetes risk following gestational diabetes mellitus (GDM), particularly its recurrence, remain limited, especially for Asian women. This study examined associations among GDM, its recurrence, and subsequent diabetes risk across multiple ethnic groups. RESEARCH DESIGN AND METHODS: This retrospective cohort study included 326,115 mothers with singleton pregnancies in the Kaiser Permanente Southern California health care system, followed from their first delivery after January 2007 until diabetes onset outside of pregnancy, end of membership, or December 2022. GDM was identified through glucose screenings during each pregnancy; diabetes was diagnosed using glucose or HbA1c levels, antidiabetes medications, or ICD codes. Cox regression models with time-varying GDM status estimated hazard ratios (HRs) and 95% CIs for diabetes risk. RESULTS: Over a median follow-up of 6.2 (IQR 2.8-10.6) years, 45,935 of 442,225 pregnancies were complicated by GDM, including 4,842 recurrent GDM pregnancies. Among all ethnic groups, Asian women had the highest GDM and recurrence rates (20.18% and 53.28%, respectively). Compared with non-GDM history, GDM was associated with a more than fivefold increased diabetes risk (HR 5.87 [95% CI 5.67-6.08]). Recurrent GDM was associated with an almost 10-fold increase in diabetes risk (HR 9.91 [95% CI 9.14-10.75]), with Asian women showing the highest risk (HR 11.74 [95% CI 9.64-14.30]). CONCLUSIONS: Compared with no GDM, GDM was significantly associated with higher diabetes risk, with recurrent GDM doubling the risk, underscoring the need for tailored screening and prevention strategies across racial and ethnic groups.