Continuous Glucose Monitoring Feedback in the Subsequent Development of Gestational Diabetes: A Pilot, Randomized, Controlled Trial in Pregnant Women

Abstract

Objective  This study evaluated the effects of receiving glucose feedback from continuous glucose monitoring (CGM) by intermittent scanning (unblinded group), and CGM with masked feedback (blinded group) in the subsequent development of gestational diabetes mellitus (GDM). Study Design  This was a prospective, single-center, pilot, randomized controlled trial including n = 206 pregnant women in the first trimester of pregnancy with no prior diagnosis of type 1 or type 2 diabetes. The participants were randomized into the unblinded group or blinded group and wore the CGM in the first trimester of pregnancy (9-13 weeks), the second trimester of pregnancy (18-23 weeks), and late-second to early-third trimester (24-31 weeks). The primary outcome was GDM rate as diagnosed by the 75-g oral glucose tolerance test (OGTT) at 24 to 28 weeks. Results  Over 47 months, 206 pregnant women were enrolled at 9 to 13 weeks. The unblinded group had a higher prevalence of women who developed GDM (21.5 vs. 14.9%; p > 0.05), compared to the blinded group. In the unblinded group compared to the blinded group, plasma glucose values were higher at 1 hour (median 7.7 [interquartile range {IQR}: 6.3-9.2] vs. 7.5 [6.3-8.7]) and 2 hours (6.3 [5.8-7.7] vs. 6.2 [5.3-7.2]), but lower at 0 hour (4.2 [4.0-4.5] vs. 4.3 [4.1-4.6]; p > 0.05). All these differences were not statistically significant. Conclusion  Glucose feedback from CGM wear in the first to the third trimester of pregnancy without personalized patient education failed to alter GDM rate. Key Points Continuous glucose monitoring (CGM) is feasible for use in pregnant women. No significant difference in gestational diabetes rates with or without CGM feedback. Future clinical trials should incorporate CGM education and personalized guidance to enhance study outcomes.