Association of early onset gestational diabetes mellitus with postpartum glucose intolerance

This study aimed to investigate the association between postpartum glucose intolerance and the timing of gestational diabetes mellitus (GDM) diagnosis according to criteria from the International Association of Diabetes and Pregnancy Study Groups (IADPSG).

A single-center retrospective case-control study involving patients diagnosed with GDM according to IADPSG criteria was conducted. Patients underwent a postpartum 75 g oral glucose tolerance test (OGTT) and were divided into 2 groups: normal (control) and abnormal glucose tolerance (AGT). Gestational age at GDM diagnosis and the maternal and neonatal outcomes were compared between the groups.

Data from 177 controls and 102 patients diagnosed with AGT were analyzed. The AGT group exhibited a higher pre-pregnancy body mass index, family history of diabetes, glycated hemoglobin level at the initial visit, and total daily insulin dose, but a lower rate of GDM diagnosis at 24-32 weeks' gestation. GDM diagnosed before 24 weeks' gestation was independently associated with AGT (adjusted odds ratio 2.18 [95% confidence interval 1.28-3.73]; p < 0.01]). Additionally, a higher proportion of patients diagnosed with GDM before 24 weeks' gestation had a lower disposition index (27.1% versus 14.8%; p = 0.01).

Patients diagnosed with GDM at < 24 weeks' gestation were at higher risk for postpartum glucose intolerance than those diagnosed at 24-32 weeks. The lower disposition index in patients early diagnosed highlights the need for tailored postpartum follow-up to address their specific risks.