1243-P: Continuous Glucose Monitoring Metrics in Gestational Diabetes—Relationship with Neonatal Outcomes and Postpartum Glucose Metabolism

Objective: Continuous glucose monitoring (CGM) has shown to improve maternal and neonatal outcomes in diabetic pregnancies. We investigated the use of CGM-derived metrics and normally monitored glucose measures in women with gestational diabetes (GDM) to study maternal and neonatal outcomes and postpartum glucose metabolism.

Methods: Sixty women with GDM were recruited prior to scheduled labor induction or caesarean section (C-section). A blinded Dexcom G6 Pro CGM was used for 10 days, starting 1-3 days predelivery. A 75-g oral glucose tolerance test (OGTT) was administered at 6-24 weeks postpartum with a subset of participants (n=28) using an additional blinded CGM for 10 days.

Results: Thirty-three participants had a vaginal delivery, 13 an unplanned (primary)C-section and 14 a repeat C-section. Infants of women having either an induction (25/33; 75.8%) or primary C-section (10/13;76.9%) were significantly more likely than repeat C-section-(4/14; 28.6%) to have neonatal hypoglycemia (χ²test= 10.7; p=0.005). Mothers treated with medication during pregnancy had a higher rate of large for gestational age (LGA) neonates and neonatal hypoglycemia (28/39; 72%) compared to diet alone (11/21; 52%) (p=.048). No direct association was demonstrated between the CGM-derived metrics prior to delivery and the postnatal glucose adaptation in the newborn. While there was only a slight positive relationship of mean glucose and glycemic variability in early postdelivery and postpartum OGTT values, there were strong linear associations of postpartum OGTT-derived estimates (mean OGTT) and postpartum CGM metrics (MBG r=.72, P<0.001; TITR r=-.74, p <0.001; MAGE r=.82 p<0.001).

Conclusion: GDM is associated with adverse pregnancy outcomes, including LGA and neonatal hypoglycemia. Further larger studies are needed to assess pre- and postpartum CGM metrics and their relationship with delivery in women with GDM, neonatal outcomes, and OGTT.