The Relationship between Antenatal Corticosteroid Administration-to-Delivery Intervals and Neonatal Respiratory Distress Syndrome and Respiratory Support.

Background: Administration of antenatal corticosteroids (ACSs) is an effective strategy for managing preterm infants, which improves neonatal respiratory distress syndrome (NRDS) and attenuates the risk of neonatal mortality. However, many preterm infants are not exposed to a complete course of ACS administration, and the effects of different ACS-to-delivery intervals on NRDS and respiratory support remain unclear. Therefore, this study explored the relationship between ACS-to-birth intervals and NRDS and respiratory support in preterm infants.

Methods: In this retrospective cohort study, the preterm infants born between 240/7 and 316/7 wks of gestation were recruited from January 2015 to July 2021. All participants were categorised based on the time interval from the first ACS dose to delivery: <24 h, 1-2 d, 2-7 d, and >7 d. Multivariable logistic regression analysis examined the relationships between the 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, the multivariable logistic analysis showed a significantly 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 the delivery room (aOR: 1.9, 95% CI: 1.0-3.7), and 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.

Conclusions: Neonatal outcomes such as NRDS, neonatal mortality, the need for surfactant use, intubation in the delivery room, and the risk of mechanical ventilation are higher when the neonates are exposed to an ACS interval for less than 24 h before delivery.