Association of Antenatal Corticosteroid Administration-to-delivery Interval With Neonatal Respiratory Distress Syndrome and Respiratory Support in Preterm Infants

Background: Administration of antenatal corticosteroids (ACS) is an effective strategy for the management of preterm infants, which can improve neonatal respiratory distress syndrome (NRDS) and attenuate the risk of neonatal mortality. However, many preterm infants do not expose to a complete course of ACS administration, and the effects of different ACS-to-delivery intervals on NRDS and respiratory support remain unclear.we explore the relationships of ACS administration-to-birth intervals with NRDS and respiratory support in preterm infants in this study.Methods: In this retrospective cohort study, the preterm infants born between 240/7 and 316/7 wk of gestation were recruited from Jan 2015 to Jul 2021. All participants were categorized based on the time interval from the first ACS dose to delivery: <24 h, 1-2 d, 2-7 d, and more >7 d. Multivariable logistic regression analysis was conducted to examine the relationships between ACS-to-birth interval and primary or secondary outcome, while adjusting for potential confounders.Results: Of the 706 eligible neonates, 264, 83, 292 and 67 received ACS-to-delivery intervals of <24 h, 1-2 d, 2-7 d and >7 d, respectively. After adjusting these confounding factors, multivariable logistic analysis showed a significant increased risk of NRDS (aOR: 1.8, 95% CI: 1.2-2.7), neonatal mortality (aOR: 2.8, 95% CI: 1.1-6.8), the need for surfactant use (aOR: 2.7, 95% CI: 1.7-4.4), endotracheal intubation in delivery room (aOR: 1.9, 95% CI: 1.0-3.7), mechanical ventilation (aOR: 1.9, 95% CI: 1.1-3.4) in the ACS-to-delivery interval of <24 h group when compared with the ACS-to-birth interval of 2-7 d group. Similar findings were observed in the subgroup analysis of the ACS interval of <6 h and 6-12 h groups (incidence of death and surfactant use), but no obvious differences were found in the ACS intervals of 12-24 h, 1-2 d and >7 d groups compared with the ACS-to-birth interval of 2-7 d group.Conclusions: Neonatal outcomes such as NRDS, neonatal mortality, the need for surfactant use, intubation in delivery room, mechanical ventilation are at a higher risk when the neonates exposed to ACS interval for less than 12 h before delivery.