Accelerated intrauterine growth in pregnancies complicated by gestational diabetes mellitus (GDM) has raised questions about whether earlier screening may improve outcomes. A dual-center, parallel, randomized controlled trial published in Diabetes Care evaluated whether advancing universal GDM screening to 18–20 weeks’ gestation improves pregnancy outcomes compared with standard screening at 24-28 weeks.

Singleton pregnant women underwent universal screening and diagnosis using a 75-g oral glucose tolerance test (OGTT) based on the International Association of the Diabetes and Pregnancy Study Groups criteria. The primary endpoint was a composite of primary cesarean delivery, birth weight greater than the 90th percentile, neonatal hypoglycemia, cord serum C-peptide greater than the 90th percentile, gestational hypertension, preeclampsia, and birth trauma. A planned interim analysis led to early trial termination for futility.

Among 967 women included in the intention-to-treat analysis, the primary composite outcome did not differ significantly between midpregnancy and standard screening groups. Neonatal hypoglycemia was significantly lower in the midpregnancy screening group. However, neonatal adiposity was higher among women with GDM diagnosed in the midpregnancy group. Adverse event rates were similar between groups.

Advancing universal GDM screening to 18-20 weeks’ gestation did not improve the composite pregnancy outcome compared with standard screening, although differences were observed in neonatal hypoglycemia and adiposity.