This study aimed to monitor the change of practice in antenatal corticosteroids use in preterm birth, assess how physicians would prescribe and identify factors associated with such a prescription. Medical records were reviewed quantitatively and current attending physicians were interviewed qualitatively. Multiple logistic regression with random effect model was used for analysis. The results revealed that antenatal corticosteroid use in preterm births initially doubled after the evidence became available and tripled after the evidence was disseminated. The antenatal corticosteroid use among women having a gestational age less than 34 weeks increased significantly from 41% to 71% and 73%, respectively (p < 0.01). A gestational age of 34 weeks or more or a higher cervical dilatation at admission reduced the use of corticosteroids significantly. In conclusion, physician’s practice changed based on the evidence. The education for the early recognition of labor and guidelines on the use of antenatal corticosteroids should be implemented.

Keywords: Antenatal corticosteroid, Preterm birth, Prophylactic corticosteroid, Evidence-based practice, Thailand