Streamlining intrapartum glycemic control: Subcutaneous insulin for intrapartum diabetes management

Optimal strategies for intrapartum glycemic control among patients with gestational diabetes mellitus (GDM) and type 2 diabetes mellitus (T2DM) remain uncertain. In 2024, our labor and delivery unit implemented a subcutaneous (SC) insulin protocol to replace routine intravenous (IV) insulin initiation when glucose exceeded a treatment threshold. We hypothesized that this change would not worsen neonatal outcomes and would improve nursing (RN) satisfaction.

We conducted a retrospective cohort quality improvement study of patients with GDM or T2DM who delivered at ≥36 weeks between March 2021 and December 2025. July 2024, when the protocol was introduced, was excluded as a washout period. The intervention included both a shift to SC insulin-first management and standardization of intrapartum glycemic treatment to a target of ≤ 120 mg/dL. The primary outcome was a composite of neonatal hypoglycemia or neonatal intensive care unit (NICU) admission for hypoglycemia within 24 h of life. Secondary outcomes included IV insulin duration and RN satisfaction. Outcomes were compared before and after implementation. Poisson regression with an interrupted time series framework assessed pre-implementation trends, immediate level changes, and post-implementation trends in the primary composite outcome. Multivariable logistic regression evaluated associations between insulin modality and the primary outcome. Surveys were analyzed by Wilcoxon rank-sum tests.

Of 1140 deliveries in the analytic cohort, the primary outcome occurred in 269 (23.6%). Rates were similar before and after protocol implementation (23.4% vs. 23.9%, p = 0.837). Interrupted time series analysis showed no significant pre-implementation trend, but did demonstrate a significant immediate reduction in monthly event rates at implementation (incidence rate ratio [IRR], 0.20; 95% confidence interval [CI], 0.04-0.90), with no significant post-implementation trend change (IRR, 1.03; 95% CI, 0.99-1.06). In adjusted analyses, insulin modality was not significantly associated with the primary outcome. RN satisfaction improved after implementation, with agreement or strong agreement increasing from 29.2% to 51.8% (p = 0.032).

Implementation of an SC insulin-first intrapartum diabetes management protocol for patients with GDM and T2DM was not associated with increased neonatal hypoglycemia nor NICU admission for hypoglycemia. The protocol was associated with improved RN satisfaction. This approach may offer a pragmatic alternative to routine IV insulin initiation during labor.