(968) Association between intrapartum glycemic control using continuous glucose monitoring and neonatal outcomes

ACOG recommends maintaining maternal euglycemia during labor to prevent neonatal hypoglycemia at birth; however, supporting data are limited. We evaluated the association between predelivery glycemic control using continuous glucose monitoring (CGM) and neonatal outcomes.

Study Design: Retrospective cohort study of patients with pregestational diabetes who used real-time CGM and delivered a live, singleton at a tertiary care center (9/2018-7/2022). Patients with major fetal anomalies were excluded. Glycemic control was measured by CGM, and time spent in target range (TIR) of 65-140mg/dL was calculated for 6hr before delivery. The p</span>rimary outcome was neonatal hypoglycemia (initial glucose < 40mg/dL). Secondary outcomes included hypoglycemia requiring treatment, initial glucose, hyperbilirubinemia, NICU admission and length of stay. Baseline characteristics and outcomes were compared between patients with TIR >70% vs TIR ≤70%. Multivariable regression estimated the association between TIR >70% and outcomes. In sensitivity analyses, we varied the exposure definition to TIR 12hr and 2hr before delivery.

Results: Of 53 included patients, 42 (79%) had TIR >70% and 11 (21%) had TIR≤70%. Patients with TIR >70% were more likely to have type 2 diabetes and higher BMI (Table 1). Neonatal hypoglycemia was less common among patients with TIR >70% compared to TIR≤70%, but it was not statistically significant (24% vs 36%, aOR 0.52, 95% CI 0.11-2.50; Table 2). Other outcomes were also similar between groups. In sensitivity analyses, there was no association between TIR >70% during 12hr before delivery and hypoglycemia (aOR 0.28, 95% CI 0.07-1.07); however, TIR >70% during 2hr before delivery was associated with a lower odds of hypoglycemia (aOR 0.01, 95% CI 0.02-0.80).

Conclusion: Maternal glycemic control immediately before delivery appears to be more important for prevention of neonatal hypoglycemia in patients with pregestational diabetes. Use of CGM data should be considered in future studies to better understand the optimal maternal glucose level and timing before delivery to minimize neonatal hypoglycemia.