Permissive intrapartum glucose control: an equivalence randomized control trial (PERMIT)

Abstract

BackgroundThere is limited high quality data to determine best practices for maternal blood glucose management during labor. ObjectiveWe compared permissive care (target maternal blood glucose 70–180 mg/dL) to usual care (blood glucose 70–110 mg/dL) among laboring individuals with diabetes. Study DesignThis was a two-site equivalence randomized control trial for individuals with diabetes (pregestational or gestational) at ≥ 34 weeks in labor. Individuals were randomly allocated to usual care or permissive care. Maternal blood glucose was evaluated by capillary blood glucose monitoring in latent and active labor every 4 and 2 hours. Insulin drip was initiated if maternal blood glucose exceeded the upper bounds of the allocated target. The primary outcome was first neonatal heel stick glucose within two hours of birth before feeding. We assumed a mean first neonatal blood glucose of 50 ±10 mg/dL. To ensure that the use of permissive care did not increase or decrease the first neonatal blood glucose >10 mg/dL (two-tailed, α= 0.05, β= 0.1), 96 total participants were required. We calculated adjusted relative risk (aRR) and 95% confidence intervals (CI) in an intention-to-treat analysis. A Bayesian analysis was preplanned to estimate the probability of equivalence with a neutral informative prior. ResultsOf 511 deliveries with diabetes assessed for eligibility (10/2022 - 6/2023), 280 (54.8%) met eligibility criteria, and 96 (34.3%) agreed and were randomized. In the usual care group, 17% required an insulin drip compared to none in permissive care. There was equivalence in the primary outcome between usual and permissive care (57.9 vs. 57.1 mg/dL, adjusted mean difference -0.72, 95% CI -8.87,7.43). Bayesian analysis indicated 98% posterior probability of mean difference not being greater than ±10 mg/dL. The rate of neonatal hypoglycemia was 25% in the usual care group and 29% in permissive group (adjusted relative risk 1.14, 95% CI 0.60, 2.17). There was no difference in other neonatal or maternal outcomes. ConclusionIn this randomized control trial, while almost 1 in 6 individuals with diabetes required an insulin drip with usual intrapartum maternal blood glucose care, permissive care was associated with equivalent neonatal blood glucose.