Gestational diabetes mellitus – Can we do better with postpartum diabetes screening?

Objective

This study aimed to assess the accuracy of measuring fasting plasma glucose (FPG) within 24–48 h postpartum in women with gestational diabetes mellitus (GDM) as a predictor for abnormal 6–12-week postpartum oral glucose tolerance test (OGTT).

Study design

A retrospective cohort study (2012–2021) included women with GDM and singleton pregnancies who had FPG levels recorded 24–28 h postpartum and underwent a 6–12-week OGTT. The study compared the predictive accuracy of these FPG readings with the OGTT results.

Results

Among 3128 GDM patients, 1163 (37.2 %) had a postpartum OGTT, with 935 (80.2 %) showing normal FPG (<100 mg/dL). In low-risk GDM cases (managed by lifestyle modifications), 86.15 % had normal postpartum FPG. Normal 24–48 h FPG readings, especially in low-risk GDM cases, had a high negative predictive value (NPV of 99.3 %) for type-2 diabetes at the 6–12-week OGTT, but a lower NPV (85.8 %) for predicting future glucose intolerance.

Discussion

Immediate postpartum FPG testing effectively excludes low-risk GDM women with regards to future type-2 diabetes and reasonably excluded future glucose intolerance in this group. Due to low compliance with standard OGTT, postpartum FPG could be a more practical predictive tool for diabetes in low-risk GDM cases.