Comparative Effectiveness of Uterotonic Agents for Postpartum Hemorrhage Prevention after Vaginal Delivery: A Retrospective Analysis of a Multicenter Prospective Cohort in Korea

Background To describe current practice patterns and compare the effectiveness and safety of uterotonic agents for postpartum hemorrhage prevention after vaginal delivery. Methods This retrospective study used data prospectively collected from a multicenter cohort derived from a registered clinical trial (NCT05122169) conducted at nine obstetric centers in South Korea between December 2021 and July 2025. Patterns of uterotonic agent use were described, followed by comparative analyses among women who underwent vaginal delivery. Postpartum hemorrhage–related outcomes, including hemoglobin decrease by ≥ 2 g/dL, blood transfusion, and invasive hemostatic interventions, were compared using unadjusted analyses and multivariable logistic regression. Results Carbetocin was the most frequently used uterotonic agent (47.8%) in 2,585 women. Its use as a monotherapy was associated with lower rates of hemoglobin decrease by ≥ 2 g/dL compared with oxytocin-only use. In multivariable analyses, carbetocin-only use tended to be associated with lower odds of hemoglobin decrease by ≥ 2 g/dL compared with oxytocin-only use, although without statistical significance. The use of carbetocin in combination with additional uterotonic agents was associated with higher odds of hemoglobin decrease by ≥ 2 g/dL compared with carbetocin-only use. Conclusions This study provides a comprehensive analysis of uterotonic agent use in Korean obstetric practice, offering an evidence-based insight into the clinical importance of carbetocin use in vaginal delivery.