The efficacy of three regimes of uterotonic agents for prevention of postpartum blood loss at undergoing cesarean section: a prospective randomized clinical trial

To compare the efficacy of three regimes of uterotonic agents on PPH in women undergoing cesarean section in our RCT. This study was a randomized controlled study (NCT05083910) performed at the Bezmialem Vakif University between July 2021 and January 2022. All women were randomly allocated into three groups: Group I (n = 52) - oxytocin only; Group II (n = 52) - the combination of oxytocin plus intrauterine misoprostol; Group III (n = 52) - carbetocin only. The primary outcome measures were: PPH to evaluate with the change between the concentrations of preoperative and postoperative hemoglobin, hematocrit and intraoperative blood loss. The blood loss characteristics, including the change in hemoglobin and the change in hematocrit concentration, intraoperative blood loss, intraoperative additional hemostatic uterine sutures and the need for additional uterotonics, were lowest in group III, although all groups were comparable in terms of blood loss parameters. Group III had the highest blood loss ratio, exceeding 1000 mL. For the combination of oxytocin and intrauterine misoprostol, the ARR was 3.8% (95% CI 20.02-12.33), with a RR of 1.18 (95% CI 0.58-2.39) and a NNT of 26 (95% CI 8.1-4.9); for carbetocin, the ARR was 5.8% (95% CI 22.15-10.61), with a RR of 1.27 (95% CI 0.63-2.53) and a NNT of 17 (95% CI 9.41-4.51). Our results demonstrate that carbetocin shows no superiority in the prevention of PPH in women undergoing cesarean section. Oxytocin still seems to be a highly effective alternative to prevent PPH.