Oral or Poster Presentation
Concurrent Session 3B - Maternal Fetal Medicine
Introduction: It is well established that the benefits of antenatal corticosteroids (ACS) for fetal lung maturation decline 7 days after administration. Yet, in clinical practice, a considerable proportion of women receive ACS >7 days before birth. Our aim was to explore the factors that affect the likelihood of administration of ACS within the ideal interval of ≤7 days from birth.
Methods: A retrospective cohort study of women who received ACS in a single tertiary centre from 2014-2017 was conducted. Per the protocol in our centre, ACS were administered to women at risk of preterm birth between 230/7 and 336/7 weeks. The ACS-to-birth interval and the proportion of women receiving ACS within 7 or 14 days before birth were stratified by indication for administration, singleton/multiples, and history of preterm birth.
Results: A total of 1,261 women were included in the analysis, of whom 401 (31.8%) and 569 (45.1%) received ACS ≤7 days and ≤14 days before birth, respectively. The proportion of women receiving ACS ≤7 days before birth was highest for those with preeclampsia (50.4%) and preterm PROM (48.1%), and was lowest for those receiving ACS for bleeding placenta previa (14.3%) and incidental finding of short cervix (8.4%) (Table). The proportion of women receiving ACS ≤7 days before birth was higher in singleton compared with multifetal gestations, and higher in women without than with a history of preterm birth (Table).
Conclusion: Over half of women do not receive ACS within the ideal interval of ≤7 days before birth. This proportion varies by indication for administration of ACS and is lowest when administered for incidental finding of short cervix. Better tools are needed to quantify the risk of preterm birth and optimize the timing of administration of ACS.