A randomized controlled trial of real-time continuous glucose monitoring (RT-CGM) for self-management of gestational...

Gestational diabetes mellitus (GDM) - a risk factor for adverse pregnancy outcomes - is on the rise. Real-time continuous glucose monitoring (RT-CGM) may enhance glucose control during GDM and thereby improve outcomes; however, more data are needed.

This study aimed to determine if RT-CGM improved glycemic indices in GDM.

An open-label, randomized controlled trial was conducted with GDM patients diagnosed between 14 and 30 weeks estimated gestational age (EGA), assigning them either to RT-CGM or blinded CGM in addition to self-monitoring of blood glucose (SMBG). This analysis compares CGM metrics for the study groups at EGA of 32 and 36 weeks (± 10 days). The primary outcome was percentage of time in range 63 to 140 mg/dL (TIR) over 24 hours. Secondary outcomes included mean glucose over 10 days and additional CGM indices, HbA1c, diabetes medication usage, satisfaction with CGM, and maternal and fetal outcomes.

105 participants with GDM were enrolled (RT-CGM [n=53] or blinded CGM [n=52]) Thirty-one of 52 SMBG participants withdrew, with 30 citing desiring RT-CGM. In participants who completed the study, average EGA was 29.8 weeks (SD=2.5) on their first day of CGM wear with average duration of wear of 64.4 days (SD=19.4). TIR 63-140 mg/dL (TIR) was 93.0 (SD=6.7) and 93.7 (SD=6.8) (p=.86) while mean glucose was 106.7 mg/dL (SD=9.0) and 98.1 mg/dL (SD=13.8) for the RT-CGM and SMBG groups (p=.02), respectively. At study completion, mean glucose and TIR were similar. Insulin and/or metformin use was 66.7% in the RT-CGM group and 33.4% in the SMBG group (p=.02). There were no significant differences in maternal or fetal outcomes. The RT-CGM group's satisfaction with CGM was high.

In this study in which CGM was initiated at about 30 weeks EGA, TIR and mean glucose were similar. However, more participants in the CGM group initiated insulin. Selection and attrition bias could have affected the results. Glycemic changes were minor, but interest in CGM was high. Further research is needed to assess if earlier implementation and use in higher risk populations may provide benefit. El resumen está disponible en Español al final del artículo.