The optimal glucose monitoring strategy in gestational diabetes mellitus (GDM) remains under investigation. An open-label, single-center randomized controlled trial, published in Diabetes Care, compared real-time continuous glucose monitoring (CGM) with capillary blood glucose (CBG) monitoring in achieving glucose time in range (%TIR) during pregnancy. The trial, conducted between February 2021 and June 2023, enrolled 111 pregnant individuals with GDM at ≥20 weeks’ gestation.

Participants were randomized in a 2:1 ratio to either CGM plus adjunctive CBG (n = 74) or CBG alone (n = 37). The intervention group used the Dexcom G6 system continuously from enrollment to delivery, while the control group used CBG four times daily and underwent blinded CGM approximately every 20 days.
The CGM group achieved significantly higher %TIR within the target range of 60–140 mg/dL (93 ± 6 vs. 88 ± 14; P = 0.027). Secondary outcomes also favored CGM, with greater daytime TIR, lower 24-hour and daytime mean glucose, and reduced time spent >140 mg/dL.

The findings demonstrate that real-time CGM provides superior glycemic control compared with CBG in pregnant individuals with GDM. Further research is needed to determine whether these improvements translate into better maternal and neonatal outcomes.