[Clinical indications and timing of antenatal corticosteroids: A single-centre retrospective study]

Preterm birth is the leading cause of neonatal mortality and remains a major public health concern. Antenatal corticosteroids (ACS) significantly reduce the complications associated with prematurity, particularly when administered between 24h and 7 days before delivery. The objective of this study was to assess the proportion of women receiving ACS within the optimal window according to clinical indication, and to identify factors that may influence timing for each indication.

We conducted a retrospective, single center observational study at Armand Trousseau Hospital (APHP, Paris) throughout 2022. Singleton pregnancies at risk of preterm birth and treated with ACS were included. The primary outcome was delivery within the optimal ACS-to-birth interval (24h-7 days), adjusted for indication. The secondary outcome was the proportion of patients who delivered at term.

Among the 185 women included, only 19% delivered within the optimal window. The mean ACS-to-delivery interval was 31.2 days. Optimal timing varied by indication: preeclampsia (40%), preterm premature rupture of membranes (31%), threatened preterm labor (6%), isolated fetal growth restriction (13%), and vaginal bleeding without cervical change (0%). No clinical factor was significantly associated with optimal timing, except for severe hypertension in the context of preeclampsia. Notably, 29% of patients delivered at term.

Most women received ACS outside the optimal therapeutic window. These findings highlight the need for predictive tools tailored to each indication to improve ACS targeting and reduce unnecessary exposure.