Impact of timing of antenatal corticosteroid exposure on neonatal outcomes

Objective. To evaluate morbidities among neonates with a history of remote antenatal corticosteroid ACS exposure compared to those with recent exposure. Study Design. This is a retrospective-cohort study of neonates born at 3033 67 weeks gestational age. The primary outcome was newborn respiratory distress syndrome RDS defined by the persistent need for oxygen at 24 h of life. Maternal chart review established timing of ACS exposure. Data were stratified by the time interval of ACS administration to delivery: none or <48 h IncompleteUnexposed, 48 h to 7 days Recent and >7 days Remote. Perinatal outcomes were compared between groups. Resuts. Five hundred and twenty-four infants were included: 273 IncompleteUnexposed, 120 Recent and 131 with Remote ACS exposure. RDS was significantly less frequent with Recent vs. Remote exposure RR: 1.73 1.013.02p 0.04. This finding persisted in a logistic regression model. Conclusions. Infants delivering more than 1 week after ACS exposure have a higher frequency of RDS than those who deliver within 1 week.