(626) Continuous Glucose Monitoring Profile Metrics in Pregnancies With and Without Adverse Neonatal Outcomes

There is controversy concerning the degree of maternal hyperglycemia associated with adverse neonatal outcomes. Continuous glucose monitoring (CGM) is an innovative technology that allows for individualized glycemic profiles.  We aimed to determine whether CGM metrics during screening for gestational diabetes (GDM) can identify individuals who experienced adverse neonatal outcomes compared to those who did not.

Study Design:

This was a prespecified, secondary analysis of a multi-clinic, randomized controlled trial of individuals being screened for GDM with the use of CGM compared to the 2-step method. Participants assigned to the 2-step method had a blinded CGM (Dexcom G6 Pro) placed at the time of the 1-hour glucose challenge test (GCT). CGM metrics evaluated included the mean glucose, time in range (TIR; 63–140 mg/dL), and time above the target range (TAR; >140mg/dL) expressed as % of all readings. The p</span>rimary outcome was a composite of neonatal adverse outcomes (CNAO), including shoulder dystocia, birth injury, large for gestational age, need for IV/PO glucose, respiratory distress, and fetal/neonatal death. We compared CGM metrics for those with or without the CNAO.

Results:

Of the 814 individuals randomized, 613 (75%) had CGM metrics that were analyzed (N=331; CGM group, N=282; 2-step blinded CGM group). Of those 196 (32%) had the CNAO and 417 (68%) did not have CNAO. The CNAO was higher among individuals diagnosed with GDM (28% v 16%; p=0.003) and those treated with hypoglycemic agents (10% v 5%, p=0.04). Neonates with the CNAO had a higher mean CGM glucose (108.9 v. 105.0, p=0.007, Figure), coefficient of variation (17.8 v. 17.1, p=0.02), and TAR (6.5% v. 3.8%, p=0.001) compared to those without (Table).

Conclusion:

In this secondary analysis, CGM metrics at 24-32 weeks of elevated mean glucose, higher coefficient of variation, and elevated TAR were associated with worse neonatal outcomes. Our findings suggest that further studies are needed to evaluate the role of various CGM metrics in diagnosing maternal hyperglycemia and related adverse outcomes.