Timing of Antenatal Corticosteroid Administration and Neonatal Outcomes

Area of Science:

• Neonatal Medicine
• Obstetrics
• Pharmacology

Background:

• Antenatal corticosteroids (ACS) are crucial for reducing neonatal mortality and morbidity associated with preterm birth.
• The optimal timing for ACS administration to maximize benefits remains incompletely defined, with current guidelines suggesting 1-7 days prior to delivery.

Purpose of the Study:

• To investigate the association between the interval from antenatal corticosteroid (ACS) administration to birth and neonatal outcomes in preterm neonates.
• To determine if the established optimal timing of 1-7 days for ACS administration is accurate.

Main Methods:

• A national retrospective cohort study analyzed data from 7950 preterm neonates (23-31 weeks gestation) born between 2018-2021.
• Restricted cubic splines modeled the association between the ACS-to-birth interval and neonatal mortality, as well as a composite of mortality or severe neurologic injury.

Main Results:

• ACS administration was linked to reduced neonatal mortality starting as early as 2 hours post-dose.
• The greatest mortality reduction was observed with intervals between 12 hours and 14 days.
• This benefit persisted for two weeks and was not affected by gestational age or plurality.

Conclusions:

• ACS administration is associated with reduced neonatal mortality from 2 hours up to 14 days after the first dose.
• The optimal interval for ACS benefit is wider than the traditional 1-7 days, extending up to 14 days.
• These findings support ACS administration even with imminent preterm birth and inform timing for repeat doses.