Gestational diabetes mellitus (GDM) is increasingly managed with continuous glucose monitoring, but evidence for improvement in glycemic indices remains limited. In the American Journal of Obstetrics & Gynecology MFM, an open-label randomized controlled trial evaluated whether real-time continuous glucose monitoring (RT-CGM) improved glycemic indices compared with blinded continuous glucose monitoring (CGM) used alongside self-monitoring of blood glucose (SMBG) in patients with GDM. Participants were diagnosed between 14 and 30 weeks estimated gestational age (EGA). This analysis compared CGM metrics at 32 and 36 weeks EGA (±10 days). The primary outcome was percentage of time in range (TIR) 63–140 mg/dL over 24 hours.

A total of 105 participants were enrolled and assigned to RT-CGM (n=53) or blinded CGM (n=52). Among participants who completed the study, mean EGA on the first day of CGM wear was 29.8 weeks (standard deviation [SD], 2.5). Mean duration of CGM use was 64.4 days (SD, 19.4). TIR was 93.0% (SD, 6.7) in the RT-CGM group and 93.7% (SD, 6.8) in the blinded CGM group (p=0.86). Mean glucose was 106.7 mg/dL (SD, 9.0) with RT-CGM and 98.1 mg/dL (SD, 13.8) with blinded CGM (p=0.02). At study completion, mean glucose and TIR were similar between groups.

Use of insulin and or metformin occurred in 66.7% of participants assigned to RT-CGM and 33.4% of those assigned to blinded CGM (p=0.02). No significant differences were observed in maternal or fetal outcomes. Satisfaction with CGM was high among participants assigned to RT-CGM.

In this randomized trial of GDM, initiating RT-CGM at approximately 30 weeks EGA did not improve TIR compared with blinded CGM, while medication initiation was more frequent and overall glycemic differences were small.