Comparison of Carbetocin and Oxytocin for the Prevention of Postpartum Hemorrhage Following Vaginal Delivery: A Double-Blind Randomized Trial

Abstract

Objectives: To compare the efficacy of a single 100 µg intramuscular (IM) carbetocin injection, a long-acting oxytocin agonist, to a 2-hour 10 IU oxytocin intravenous (IV) infusion, in reducing the incidence and severity of postpartum hemorrhage (PPH) in women at risk for this condition.Methods: A randomized, double-blind, placebo-controlled study was conducted at 2 hospital centres, including 160 women with at least I risk factor for PPH. Eighty-three women received 100 µg carbetocin IM and an IV placebo immediately after placental delivery, while 77 women received placebo IM and oxytocin IV infusion. Complete blood count was collected at entry and 24 hours postpartum. All outcome measures, including the need for additional uterotonic agents or uterine massage, blood loss, and drop in hemoglobin and hematocrit, were analyzed using chi-square, Fisher exact, and Student t tests.Results: Population profile and risk factors for PPH were similar for each group. No significant difference was observed in the number of women requiring additional uterotonic medication (12 in each group). However, in the carbetocin group, 36 of the 83 women (43.4%) required at least I uterine massage compared to 48 of the 77 women (62.3%) in the oxytocin group (P < .02). Overall, uterotonic intervention was clinically indicated in 37 of the women (44.6%) receiving carbetocin compared to 49 of the women (63.6%) given an IV oxytocin infusion (P < .02). There were no differences in laboratory PPH indicators between the 2 groups.Conclusions: Women receiving a single 100 µg IM carbetocin injection required significantly less uterotonic intervention compared to women receiving a continuous 2-hour IV oxytocin infusion. A single IM carbetocin injection is more likely to prevent PPH in women at risk when compared to a continuous oxytocin IV infusion.