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 steroids (ANS) administration and its interaction with pre-eclampsia (PE) on respiratory outcome among infants born preterm.

Study Design: This was an analysis of a prospective, single-center cohort of infants born between 23 to 30 weeks of gestation between 2012 through 2021. Endpoints were severe RDS (sRDS) and moderate-severe BPD (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 PE with the endpoints.

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

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