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 (November 2021-December 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 fingerstick (FS) according to usual care. The primary outcome was NH. Secondary neonatal outcomes included neonatal intensive care unit (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) and time above the target range (TAR; >110 mg/dL) were expressed as a percentage 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 the 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 (interquartile range [IQR]:89.9, 113.5 mg/dL), and the average percentage of TIR was 62.1% (IQR, 36.9, 85.6). CGM and FS were poor predictors of NH, with no differences in area under the curve (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 cut-off 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% versus ≤61% was 45.8 versus 25.9% (p = 0.06). Neonates born to individuals with TAR >61% were more likely to require continuous positive airway pressure after delivery and had a higher cord c-peptide level.

Conclusion:  In this prospective study of laboring individuals with diabetes, intrapartum CGM TAR was associated with a higher rate of NH.

Key points: · CGM use in labor is feasible with a complete glucose profile in the various stages of labor.. · Best cut-off for predicting NH was a time above range (≥110 mg/dl) of >61%.. · CGM and FS were poor predictors of NH..