The Interaction of Antenatal Steroid Timing and Pre-Eclampsia on Respiratory Outcomes Among Infants Born Preterm.

Objective: To evaluate the effect of timing of antenatal steroid (ANS) administration and its interaction with pre-eclampsia on respiratory outcome among infants born preterm.

Study Design: This was an analysis of a prospective, single-center cohort of infants born between 23 and 30 weeks of gestation between 2012 through 2021. End points were severe respiratory distress syndrome (sRDS) and moderate-to-severe bronchopulmonary dysplasia (msBPD). ANS administration was classified as within 7 days of birth or earlier than 7 days before birth. Multivariable generalized estimating equations were used to model the association between ANS timing and pre-eclampsia with the end points.

Results: The cohort included 1172 infants, of whom 30% were born to mothers with pre-eclampsia and 83% to mothers who received ANS within 7 days of birth. Compared with non-pre-eclampsia with ANS within 7 days of birth, pre-eclampsia with ANS earlier than 7 days before birth was associated with an increased risk for sRDS. Pre-eclampsia with ANS within 7 days of birth was not associated with an increased risk for sRDS. Compared with non-pre-eclampsia with ANS within 7 days of birth, non-pre-eclampsia with ANS earlier than 7 days of birth, and pre-eclampsia with ANS earlier than 7 days before birth were associated with an increased risk for msBPD. Pre-eclampsia with ANS within 7 days of birth was not associated with increased risk of msBPD.

Conclusions: In this cohort, properly timed maternal ANS administration within 7 days of birth was associated with a reduced risk of sRDS and msBPD among infants born preterm to mothers with pre-eclampsia. These findings underscore the need to optimize the timing of ANS administration.