Relationship Between Intrapartum Continuous Glucose Monitoring Values and Neonatal Hypoglycemia in Individuals with Diabetes

Objective: We aimed to evaluate the relationship between intrapartum continuous glucose monitoring (CGM) and neonatal hypoglycemia (NH) in individuals with diabetes. Study design: a multicenter prospective study (11/2021-12/2022) of laboring individuals with pregestational or gestational diabetes at ≥ 34 weeks. Cohorts had a blinded CGM placed from admission through delivery and were monitored with fingersticks (FS) according to usual care. Primary outcome was NH. Secondary neonatal outcomes included NICU length of stay, need for intravenous (IV) glucose therapy, hyperbilirubinemia, respiratory distress or respiratory distress syndrome. Time in the target range (TIR; range 70–110 mg/dL), time above the target range (TAR; >110mg/dL) expressed as % of all CGM readings, and mean glucose was obtained. Youden index was used to choose the cut point for TAR and prediction of NH. Results: Of 9,479 deliveries during the study period, 202 (2.1%) met inclusion criteria, and 112 (56%) participants were enrolled (n=7 did not have available CGM data). Of the study participants, 45 (40%) had pregestational diabetes, and 67 (60%) had gestational diabetes. The mean glucose in labor using a CGM was 102.6 mg/dL (IQR 89.9, 113.5 mg/dL), and the average % of TIR was 62.1% (IQR, 36.9, 85.6). CGM and FS were poor predictors of NH, with no differences in AUC of mean glucose as a predictor (0.64, 95% CI 0.48-0.23 vs. 0.53, 95% CI 0.4-0.6, respectively). The best cutoff for the prediction of NH was a TAR of 61%, with 23% (n=24) being above the threshold. The rate of NH for TAR>61% vs ≤61% was 45.8% vs 25.9% (p=0.06). Neonates born to individuals with TAR>61% were more likely to require CPAP after delivery and had a higher cord c-peptide level. Conclusions: In this prospective study of laboring individuals with diabetes, intrapartum CGM TAR was associated with a higher rate of neonatal hypoglycemia