INTRODUCTION: The World Health Organisation endorses the administration of antenatal corticosteroids (ACS) in pregnant women at risk of preterm birth between 24 0/7 and 33 6/7 weeks of gestation because it improves neonatal outcomes. However, these recommendations do not extend to women at risk of preterm delivery beyond 34 weeks, “the late pre-term period”, due to a paucity of safety literature for this cohort. Nearly 70% of all preterm deliveries are late-preterm (34 0/7 to 36 6/7 weeks of gestation) and these neonates are more susceptible to adverse respiratory and other outcomes than those born at term. Our aim was to study the risks and benefits of using ACS in the late-preterm period.
METHODS: We conducted a retrospective cohort study of all singleton preterm deliveries from 34 0/7 to 36 6/7 weeks of gestation at a university hospital from 2012 to 2017. Data were collected on ACS administration and neonatal outcomes after exclusion criteria were applied. Univariate, multivariate and stratified analysis were carried out to compare the neonatal outcomes between mothers who received ACS and those who did not.
RESULTS: A database was established comprising 228 subjects that received ACS and 610 that did not. Administration of ACS significantly reduced the incidence of transient tachypnoea of the newborn (3.9% vs. 8.2%, p=0.047). This relationship holds true after adjusting for potential confounders including gestational age, caesarean delivery, infant gender, parity, pre-eclampsia, maternal gestational diabetes and smoking (aOR=0.276, 95% CI 0.122–0.624). Significantly higher rates of neonatal hypoglycaemia and admission to special care nursery were observed in infants exposed to ACS. However, these associations became non-significant after adjusting for the aforementioned confounders (aOR=1.423, 95% CI 0.962–2.105, and aOR=1.281, 95% CI 0.786–2.088). We found no significant between-group differences in the incidence of respiratory distress syndrome, presumed sepsis, jaundice requiring phototherapy, and the duration of respiratory support.
CONCLUSIONS: Administration of ACS in late preterm birth was associated with a significant decrease in transient tachypnoea of the newborn but not in other neonatal morbidities. We demonstrated no immediate adverse outcomes associated with ACS.