64-OR: Continuous Glucose Monitoring among Pregnant Individuals with Glucose Intolerance

Introduction & Objective: Glucose intolerance is common in pregnancy but incompletely characterized. We used continuous glucose monitor (CGM)-derived metrics to assess dysglycemia amongst pregnant individuals with a varying levels of glucose intolerance.

Methods: In this prospective observational study, pregnant individuals between 24-32 weeks gestation with no history of pregestational diabetes wore blinded CGM for up to 10 days. Participants were separated into four cohorts: normal 1-hour glucose challenge test (GCT), abnormal GCT and normal 3-hour oral glucose tolerance test (OGTT), abnormal GCT and 1 abnormal value on OGTT, and GDM by Carpenter-Coustan criteria. We calculated summary statistics and tested between-group differences with one-way ANOVA pair-wise comparisons with the prespecified primary outcome of time in range (TIR) within the pregnancy-specific goal of 63-140 mg/dL. We used one-way ANOVA and post-hoc tests for secondary outcomes of average glucose, time hyperglycemic, and coefficient of variation.

Results: Among 71 pregnant individuals at a mean gestational age of 29 weeks, the mean CGM use was 7.6 days. The mean time in range for the normal GCT cohort was 96.6% (95% CI 94.9-97.8%), for failed GCT/normal OGTT was 92.0% (95% CI 89.6-96%), for failed GCT/1 abnormal OGTT value was 91.8% (95% CI 83.7-95.7%), and for GDM was 92.6% (95% CI 83.9-97.9%). Normal GCT TIR was significantly different from failed GCT and 1 abnormal OGTT (p=0.04) and GDM (p= 0.04); no other pairwise comparisons of TIR were significantly different. There were no significant between-group differences for average glucose (p= 0.31), time hyperglycemic (p= 0.17), and coefficient of variation (p= 0.10).

Conclusion: Pregnant individuals with 1 abnormal OGTT value had similar TIR as those with a diagnosis of GDM. Further research is needed to determine if these individuals have clinically significant dysglycemia associated with adverse pregnancy outcomes that requires monitoring and intervention.