Targeting Global Coverage: Comparison of In-Hospital OGTT at 2-3 Days Postpartum with OGTT at 6-12 Weeks Postpartum for Predicting Glucose Intolerance in Postpartum Women with Gestational Diabetes Mellitus.

Background: Recognizing the importance of postpartum testing for dysglycaemia after gestational diabetes mellitus (GDM), follow-up visit is recommended by all guidelines; unfortunately, dropout rate for follow-up is very high.

Objective: Comparison of diagnostic accuracy of early OGTT on day 2 or 3 postpartum with late OGTT at 6-12 weeks for predicting dysglycaemia in women with GDM in index pregnancy.

Methods: A total of 250 women with GDM underwent early WHO OGTT testing at 2-3 days postpartum, repeated at 6-12 weeks postpartum. Diagnostic accuracy, sensitivity, specificity, AUC, NPV, and PPV of early OGTT were calculated with 6-12 weeks OGTT as the gold standard.

Results: Of the 250 women, 100% completed glucose testing at 2-3 days postpartum while 86% returned at 6-12 weeks for repeat testing despite repetitive phone calls. At 2-3 days of testing, 26.80% women had impaired fasting glucose (IFT), 26.40% women had impaired glucose tolerance (IGT), and 3.20% women had DM. At 6-12 weeks testing, 25% had IFT, 29.81% had IGT. Early OGTT had a sensitivity of 86.15%, specificity of 91.61%, AUC of 0.89, NPV of 93.57%, PPV of 82.35% for predicting dysglycaemia. 51.6% were found to be suffering from metabolic syndrome during 2nd postpartum visit.

Conclusion: Early OGTT has the advantage of 100% coverage of women with GDM and may have comparable accuracy to conventional OGTT at 6-12 weeks postpartum in detecting impaired glucose status. Counselling and appropriate intervention before discharge may support prevention or delay the progression of diabetes and associated metabolic disorders.