(416) Intrapartum Glycemic Control with IV Insulin Infusion in Pregestational and Gestational Diabetes

Objective: ACOG recommends maintaining maternal glucose < 110mg/dL in labor, often managed with IV insulin infusion. Our objective was to describe the degree of intrapartum glycemic control achieved with IV insulin infusion and identify factors associated with intrapartum glycemic control.

Study Design: A retrospective cohort study of pregnant persons with pregestational or gestational diabetes who received IV insulin infusion during labor at a tertiary center was conducted (2015-2024). Antepartum fetal demise and deliveries < 22 weeks were excluded. At our center, IV insulin titration is individualized by clinicians based on hourly glucose values and response to prior adjustments. The primary outcome was percentage of intrapartum glucose values within target range of 65-110mg/dL (TIR_Labor). We compared TIR_L and other glycemic measures by diabetes type. Multivariable linear regression with backward stepwise selection was used to identify sociodemographic and clinical factors associated with TIR_L.

Results: Of 896 included persons, 49 (5%) had A1GDM, 305 (34%) had A2GDM, 365 (41%) had T2DM, and 177 (20%) had T1DM. Overall, 52% were non-Hispanic Black, 32% non-Hispanic White, 14% Hispanic; 65% had government insurance; mean BMI was 40±9 kg/m2; mean delivery GA was 35.8±3.2 weeks; and 72% had labor induction. The mean TIRL was 51±33% with differences in glycemic control by diabetes type (Table 1). A2GDM (vs T1D), labor induction, use of SMBG (vs CGM) for monitoring, greater number of intrapartum glucose measurements and later delivery year were associated with higher TIR_L, whereas higher HbA1c and corticosteroids < 7 days before delivery were associated with lower TIR_L (Table 2).

Conclusion: Strict intrapartum glycemic control (65-110 mg/dL) is difficult to achieve with clinician-managed IV insulin infusion. Future interventions to improve intrapartum control including alternatives to clinician-managed IV insulin should address potential barriers such as diabetes type, suboptimal glycemic control before admission, recent antenatal corticosteroids, and short labor duration with fewer intrapartum glucose measurements.