Intrapartum glucose metrics associated with adverse neonatal outcomes among people with gestational diabetes mellitus

Abstract Introduction Hyperglycemia is a recognized risk factor for adverse neonatal outcomes. However, the impact of achieving glucose goals during labor on the risk of such outcomes remains poorly understood for individuals with gestational diabetes mellitus (GDM). We sought to compare continuous glucose monitoring (CGM) metrics between laboring GDM pregnancies complicated by adverse neonatal outcomes to those without complications. Methods Secondary analysis of pregnant people with GDM randomized to using CGM versus capillary blood glucose (CBG) for management of GDM. Among all participants wearing a CGM during labor, we compared pregnancies that were complicated by a significant neonatal outcome as defined by a composite including one or more of the following: hypoglycemia, hyperbilirubinemia, respiratory distress syndrome, or neonatal intensive care unit admission to those without this composite adverse outcome. Continuous variables were compared with two‐sample t ‐tests, and categorical variables were tested with Fisher's Exact tests. We correlated antepartum to intrapartum glucose management by measuring mean glucose and glucose percent time‐in‐range (TIR; primary intrapartum range 70–120 mg/dL, with candidate ranges 70–110 and 70–140 mg/dL), stratified by composite adverse neonatal outcome. Results Of the 111 in the primary trial, 59 were included in this secondary analysis. A total of 52 of 111 patients in the primary trial were excluded, as 23 were missing intrapartum data and 29 had no trial of labor prior to cesarean delivery. The cohort with the composite adverse neonatal outcome spent significantly less intrapartum TIR between 70 and 120 mg/dL (62.7% vs. 80.7%, p = 0.012) and more time‐above‐range (TAR) ≥ 120 mg/dL (26.7% vs. 10.6%, p = 0.007) compared to those with no composite adverse neonatal outcome. The mean glucose for those with adverse neonatal outcomes was non‐significantly higher than those without (103.9 vs. 94.6, p = 0.059). There was a weak‐to‐moderate positive correlation between antenatal and intrapartum glucose management. Conclusion Intrapartum participants with GDM and a composite adverse neonatal outcome spent less TIR, more TAR, with a higher mean glucose in labor than those without a composite adverse outcome. A weak‐to‐moderate positive correlation between antenatal and intrapartum glucose management was observed.