Prophylactic Administration of Uterotonics to Prevent Postpartum Hemorrhage in Women Undergoing Cesarean Delivery for Arrest of Labor: A Randomized Controlled Trial

Objective: To evaluate whether prophylactic administration of oxytocin plus ergonovine or oxytocin plus carboprost is more effective than oxytocin alone in reducing the need for additional uterotonics among women undergoing cesarean delivery for labor arrest.

Methods: In this double-blind, three-arm randomized controlled trial, participants were assigned to receive either oxytocin 5 units intravenous alone, or with ergonovine 0.25 mg intravenous or carboprost 0.25 mg intramuscular immediately after delivery, followed with maintenance infusion of oxytocin 40 milliunits/minute in all groups. Uterine tone was assessed at 3, 5, and 10 minutes after delivery, and additional uterotonics were administered if deemed necessary. The primary outcome was intraoperative need for additional uterotonics. Secondary outcomes included uterine tone, calculated blood loss, and side effects. A sample size of 34 per group (n=102), based on the null hypothesis that there is no association between treatment assignment and the need for additional uterotonics, permitted independent post hoc pairwise comparisons between oxytocin plus ergonovine, oxytocin plus carboprost, and oxytocin alone using an adjusted P-value of .025. The association between the need for additional uterotonics and treatment group was assessed using the χ2 test.

Results: From June 2013 through July 2019, 105 participants were randomized (35 per group) and data from 100 participants were analyzed: oxytocin (n=35), oxytocin plus ergonovine (n=33), and oxytocin plus carboprost (n=32). There was no difference in the requirement of additional intraoperative uterotonics across groups (oxytocin [37%] vs oxytocin plus ergonovine [33%] vs oxytocin plus carboprost [34%], P=.932). Uterine tone and calculated blood loss were similar across groups. Incidence of nausea or vomiting was higher in oxytocin plus ergonovine (85%; odds ratio [OR] 5.3, 95% CI 1.7-16.9, P=.003) and oxytocin plus carboprost (72%; OR 2.4, 95% CI 0.9-6.7, P=.086) compared with the oxytocin (51%) group.

Conclusion: Compared with oxytocin alone, prophylactic use of a combination of uterotonic drugs did not reduce the need for additional uterotonics at cesarean delivery for labor arrest.

Clinical trial registration: ClinicalTrials.gov, NCT01869556.