Outcome trends in preterm infants with incomplete antenatal corticosteroid cycles: Is 6 h enough?

Large studies continue to demonstrate that the timing of antenatal corticosteroids (ACS) is often suboptimal. New research is examining alternative dosing and timing. This analysis examines outcome trends for infants with incomplete ACS cycles.

This is a secondary analysis of a retrospective cohort study (Kraft 2024) analyzing 539 deliveries from January 2008 through December 2015 between 22^0/7 and 29^6/7 gestational weeks at the Department of Obstetrics and Gynecology of the University Hospital in Ulm. Time from initiation of ACS to delivery was categorized using cutoffs of <6 h, 6-12 h, 12-24 h, 24-36 h, and > 36 h. The primary endpoint was a composite endpoint of the events bronchopulmonary dysplasia (BPD), intraventricular hemorrhage grade 4 (IVH), death, necrotizing enterocolitis (NEC), surfactant administration (used as a marker for respiratory distress), retinopathy of prematurity (ROP), and sepsis. Each event was additionally analysed independently, considered as a secondary endpoint, and analyzed with ACS timing using generalized estimation equations with logit link and exchangeable correlation structure to account for dependency in the data (multiple births).

Infants with higher gestational age within the ACS timing groups experienced severe outcomes less often (all OR < 1). Regarding the composite endpoint, differences between the ACS timing groups could not be shown (p = 0.193). However, grouping variable "<6 h" had the highest chance for adverse composite endpoint compared to the group > 36 h (OR = 1.97; 95 % CI: [0.89; 4.71].

We lack sufficient studies examining shorter ACS intervals. Preliminary results show a trend that a cut off of 6 h may be sufficient in reducing the risk of adverse outcomes.