Real-Time Continuous Glucose Monitoring in Pregnancies With Gestational Diabetes Mellitus: A Randomized Controlled Trial.

OBJECTIVE

To compare the efficacy of real-time continuous glucose monitoring (CGM; intervention) with capillary blood glucose (CBG) monitoring (control) alone to achieve greater percent glucose time in range (%TIR) among pregnant individuals diagnosed gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

This was an open-label, single-center, randomized controlled trial of pregnant individuals with GDM and ≥20 weeks' gestation. Subjects were randomly assigned (2:1) to use real-time CGM plus adjunctive CBG versus CBG alone for glucose monitoring. The intervention group was instructed on the continuous use of the Dexcom G6 CGM system from enrollment to admission for delivery. The control group used CBG monitoring four times per day underwent blinded CGM approximately every 20 days throughout the study period. The primary outcome was the CGM %TIR defined as 60-140 mg/dL (3.3-7.8 mmol/L) from study enrollment until hospital admission for delivery.

RESULTS

A total of 111 participants were enrolled between February 2021 and June 2023 (n = 74 in intervention group; n = 37 in control group) with no statistical differences in demographic characteristics between the groups. The CGM group had significantly higher %TIR ±SD (93 ± 6 min vs. 88 ± 14 min at 60-140 mg/dL; P = 0.027). Among key secondary CGM metric outcomes, the intervention group had significantly higher daytime TIR with lower 24-h and daytime mean glucose and percent time >140 mg/dL compared with the control group.

CONCLUSIONS

We demonstrated a significantly higher %TIR using real-time CGM compared with CBG glucose monitoring among pregnant people with GDM. Studies are needed to determine if achieving lower CGM glucose levels can improve perinatal and neonatal outcomes.