Timing of gestational diabetes diagnosis and progression to type 2 Diabetes: A comparative analysis.

AIM:To evaluate and compare the risk of progressing to type 2 diabetes (T2DM) based on the timing of gestational diabetes (GDM) diagnosis during pregnancy. METHODS:Retrospective analysis of pregnant individuals with gestational diabetes and post-pregnancy follow up. Data sourced from Meuhedet HMO's computerized laboratory system, cross-tabulated with the Israeli National Diabetes Registry. The cohort was divided into normoglycemic, early GDM (diagnosed by fasting plasma glucose 92-125 mg/dL (5.1-6.9 mM) at < 15 weeks), 2nd trimester GDM (diagnosed at 24-28 weeks), and late GDM (diagnosed after 29 weeks). Statistics included univariate analysis followed by survival analysis. Risk was further analyzed for individuals by obesity status. RESULTS:75,459 entered the analysis: 90 % normoglycemic, 7.9 % early GDM, 1.4 % 2nd trimester GDM, and 0.7 % late GDM. Median post-pregnancy follow-up time was 4.3 (IQR 3.3-5.1). 2nd trimester GDM showed the highest T2DM risk annually after pregnancy. Cox regression analysis, adjusted for confounders, revealed a significantly higher T2DM risk for 2nd-trimester GDM compared to early and late GDM. Late GDM did not confer additional significant T2DM risk. Stratification by obesity status highlighted that early GDM increased the risk of T2DM only in individuals without obesity. CONCLUSIONS:GDM diagnosis timing significantly impacts T2DM risk. 2nd trimester GDM carries the highest T2DM risk.