Gestational diabetes mellitus and late preterm birth: outcomes with and without antenatal corticosteroid exposure

Abstract

BackgroundUnlike pregestational diabetes, ACOG recommends antenatal corticosteroids in those with GDM at risk for preterm birth. However, this recommendation is based on limited data, only 10.6% of the Antenatal Late Preterm Steroids (ALPS) study sample had GDM. There is a paucity of data on the risk of neonatal respiratory and other morbidity in this population. ObjectiveTo examine respiratory outcomes in parturients with GDM who received antenatal corticosteroids and delivered during the late preterm period versus those who did not. Material and MethodsThis population-based cohort study used the U.S. Vital Statistics dataset between 2016 to 2020. The inclusion criteria were singleton, non-anomalous individuals who delivered between 34.0 to 36.6 weeks with GDM and known status of antepartum corticosteroid exposure. The primary outcome, a composite neonatal adverse outcome (CNAO), included: Apgar score < 5 at 5 minutes, immediate assisted ventilation, assisted ventilation> 6 hours, surfactant use, seizure, or neonatal mortality. The secondary outcome was composite maternal adverse outcome (CMAO) including maternal blood transfusion, ruptured uterus, unplanned hysterectomy, and admission to the intensive care unit (ICU). Multivariable Poisson regression models were used to estimate adjusted relative risks (aRR) and 95% confidence intervals (CI). Average annual percent change (AAPC) was calculated to assess changes in rates of corticosteroid exposure over the study period. ResultsOf 19 million births during the study period, 110,197 (0.6%) met inclusion criteria, and among them, 23,028 (20.9%) individuals with GDM received antenatal corticosteroids. The rate of antenatal steroid exposure remained stable over the 5 years (APC=10.7, 95% CI: -5.4, 29.4). The CNAO was significantly higher among those who received corticosteroids than those who did not (137.1 versus 216.5 per 1,000 live births; aRR 1.24, 95% CI 1.20-1.28). Three components of the CNAO—immediate assisted ventilation, intubation > 6 hours, and surfactant use—were significantly higher with exposure than without. Additionally, the CMAO was significantly higher among those who received corticosteroids (aRR 1.34, 95% CI 1.18-1.52). Three components of CMAO—admission to ICU, blood transfusion, and unplanned hysterectomy—were significantly higher among the exposed group. Subgroup analysis, among large-for-gestational age, by gestational age, and race and ethnicity, confirm the trend of increased likelihood of adverse outcomes with exposure to corticosteroid. ConclusionIndividuals with GDM and antenatal corticosteroid exposure versus those unexposed, who delivered in the late preterm were at higher risk of neonatal and maternal adverse outcomes.