Objective: To compare the effectiveness of carbetocin and oxytocin in the prevention of postpartum hemorrhage (PPH) in terms of additional drug use after Cesarean sections in high-risk women.

Materials and Methods: A double-blind randomized controlled trial (1:1 ratio) conducted between October 2018 and April 2019 at Rajavithi Hospital in 120 singleton pregnant women that undergone elective or emergency Cesarean sections after 34 weeks of gestation with viable fetuses and presenting at least one of the high-risk factors for PPH. The participants were randomized to receive either intravenous carbetocin 100 μg (60 cases) or oxytocin 20 IU in 1,000 mL of lactate ringer solution as infusion 120 mL/hour (60 cases) after birth of the baby or delivery of the placenta.

Results: The mean maternal age, BMI, gestational age at delivery, and risk factors for PPH were not significantly different between the carbetocin and the oxytocin group. A previous Cesarean section was the most common risk factor in both groups. Most of the participants in both groups were multiparity. There was a significant difference between the carbetocin and oxytocin groups in terms of additional uterotonic drug usage at 20.0% versus 36.7% (p=0.04), while the type of uterotonic agents and time from post-delivery until the administration additional drugs were not different. The estimated blood loss, rate of PPH, operative time, or adverse drug effect were comparable between the two groups.

Conclusion: The carbetocin group requires less additional uterotonic drugs than the oxytocin group with equal safety profiles. However, its effectiveness in the prevention of PPH is debatable since the incidence of PPH observed was not significantly different. Further studies including the efficacy of the drug in preventing PPH and cost-effectiveness analysis with a larger sample size should be performed.