Utilization of Carbetocin for Prevention of Postpartum Hemorrhage After Cesarean Section: A Randomized Clinical Trial

Abstract

Expectant management for the third stage of labor is widely used, despite the risk of postpartum hemorrhage (PPH) and the availability of the safer and more effective alternative of active management using oxytocics. A long-acting oxytocin analog, carbetocin, has shown promise in the prevention of uterine atony after cesarean section (CS). This randomized controlled study compared the effectiveness of a single intravenous (IV) injection of carbetocin with that of a standard 2-hour IV infusion of oxytocin in preventing uterine atony and reducing the incidence and severity of PPH following cesarean section. The safety and ability of the 2 treatments to maintain adequate uterine tone were also compared. A total of 104 singleton term pregnant women scheduled for CS who had at least one risk factor for PPH were divided into 2 groups: Women in group 1 (n = 52) received 100 μg carbetocin IV immediately after placental delivery and women in group 2 (n = 52) received 10 IU of oxytocin by IV infusion. The primary study outcome was the proportion of women in the 2 groups who required additional oxytocic intervention for uterine atony. The need for uterine massage, and the extent of blood loss were also assessed. There was a complete blood count at entry and 24 hours postpartum. The effectiveness of a single 100 μg IV injection of carbetocin in controlling intraoperative blood loss after placental delivery was similar to that of a continuous 2-hour infusion of oxytocin: mean blood loss with carbetocin was 370.1 mL compared to 400.1 mL with oxytocin (P < 0.05.). The percentage of patients with blood loss less than 500 mL occurred, was higher with carbetocin (81 % vs. 55%; P = 0.05). Early postpartum uterine involution was higher in carbetocin. The percentage of patients with the fundus below the umbilicus at 24 hours postpartum was higher among women receiving carbetocin (P < 0.05). A smaller percentage of women in the carbetocin group (38.4%, 20/52) required at least one uterine massage compared to those in the oxytocin group (57.7%, 30/52) (P < 0.01). There was a clinical indication for additional uterotonic intervention in 2 women (3.8%) in the carbetocin group compared to 5 (9.6%) in the oxytocin group (P < 0.01). The odds ratio of treatment failure requiring oxytocic intervention was 1.83 times higher with the oxytocin group; the 95% confidence interval was 0.9 to 2.6. No significant differences between the groups were found in the type and frequency of adverse effects. These findings suggest that carbetocin is a promising therapeutic alternative to oxytocin in the prevention of uterine atony after delivery by CS.