Treatment Creep Of Antenatal Late Preterm Steroids

While antenatal corticosteroids (ACS) administered in the late preterm period have been shown to reduce neonatal respiratory morbidity, this finding was demonstrated in a well-designed randomized controlled trial (ALPS) with strict inclusion/exclusion criteria that may not be adhered to in typical practice. The aim of this study was to investigate whether there has been treatment creep since use of late preterm ACS became standard of care. Retrospective cohort study of pregnant women who received late preterm ACS between 2016 and 2019 were identified and separated into epochs of 2016-2017 and 2018-2019 based upon year of ACS exposure. The primary outcome was rate of inappropriate ACS exposure, defined as non-adherence to the inclusion/exclusion criteria of the ALPS trial. Secondary outcomes were rates of non-optimal ACS exposure (delivery >7 days from ACS or term delivery). Logistic regression was used to generate adjusted odds ratios (aOR) between epochs for the primary outcome adjusting for confounders. There were 660 women who received late preterm ACS during the study period with 229 (34.6 %) deemed inappropriate exposures. The most common reason for inappropriate treatment was PPROM (29.0%) with exclusionary cervical exam or contraction frequency (Figure 1). No difference was observed in inappropriate ACS exposure across the study period (37.1% vs 32.6%, aOR 0.83, CI 0.59-1.2). However, there was a reduced probability of non-optimal exposure over time (Table 1). Women receiving inappropriate ACS were more likely to deliver at term if indicated for maternal/fetal status (50.0% vs 19.5%; p7 days (62.3% vs 39.1%; p=.006) with a significant longer latency to delivery (3 vs 16 days; p