Antenatal corticosteroids and neurodevelopmental outcomes in late preterm births

Objectives Antenatal corticosteroids (ACS) decrease neonatal mortality and morbidity among preterm neonates, yet there has been concern regarding their long-term safety. We hypothesised that potential long-term adverse effects of ACS may be observed among infants born during the late preterm period (LPT, 34(0/7)-36(6/7) weeks of gestation), when the benefits of ACS are subtle. Design Population-based, retrospective cohort. Setting Ontario, Canada, between 2006 and 2011. Patients All live singleton infants born during the LPT period with a minimum 5-year follow-up. Interventions Exposure to ACS prior to 34(0/7) weeks of gestation. Main outcome measures Suspected neurocognitive disorder, audiometry testing or visual testing. Results Overall, 25 668 infants were eligible for analysis, of whom 2689 (10.5%) received ACS. Infants in the ACS group had lower mean birth weight and higher rates of birth weight <10th percentile, neonatal resuscitation and neonatal intensive care unit admission. At 5 years of age, ACS exposure was associated with an increased risk of suspected neurocognitive disorder (adjusted HR (aHR) 1.12, 95% CI 1.05 to 1.20), audiometry testing (aHR 1.20, 95% CI 1.10 to 1.31) and visual testing (aHR 1.06, 95% CI 1.01 to 1.11). Conclusion In children born during the LPT period, exposure to ACS prior to 34(0/7) weeks of gestation is associated with an increased utilisation of the healthcare system related to audiometry and visual testing and suspected neurocognitive disorders by 5 years of age. In a large population-based dataset of live births at 34-36 weeks' gestation born 2006-2011, exposure to antenatal corticosteroids earlier in gestation may be associated with an increased risk for neurodevelopmental concerns and healthcare utilization at 5-9 years.

Automated summary

In a retrospective cohort study conducted in Ontario, Canada between 2006 and 2011, exposure to antenatal corticosteroids earlier in gestation was associated with an increased risk for neurodevelopmental concerns and healthcare utilization at ages 5-9 among children born during the late preterm period. This study adds to concerns regarding the long-term safety of antenatal corticosteroid use, particularly in late preterm infants.