For a study, researchers wanted to determine if oxytocin with ergonovine or oxytocin plus carboprost is more efficacious than oxytocin alone in minimizing the need for further uterotonics in women undergoing cesarean birth for labor arrest. Participants in this double-blind, three-arm randomized controlled trial were randomly 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 by oxytocin 40 milliunits/minute maintenance infusion in all groups. The uterine tone was measured 3, 5, and 10 minutes after birth, and more uterotonics were given if required. The key result was the requirement for extra uterotonics during surgery. Uterine tone estimated blood loss and side effects were all secondary results. Based on the null hypothesis that there is no association between treatment assignment and the need for additional uterotonics, a sample size of 34 per group (n=102) allowed for independent post hoc pairwise comparisons of oxytocin plus ergonovine, oxytocin plus carboprost, and oxytocin alone using an adjusted P-value of.025. The 2 test was used to investigate the relationship between the requirement for extra uterotonics and the treatment group.

From June 2013 to July 2019, 105 people were randomly assigned to one of three groups (oxytocin (n=35), oxytocin plus ergonovine (n=33), and oxytocin plus carboprost (n=32), and data from 100 participants were evaluated. There was no difference in the need for further intraoperative uterotonics between groups (oxytocin [37%] vs oxytocin plus ergonovine [33%] vs oxytocin plus carboprost [34%], P=.932). Uterine tone and estimated blood loss were comparable between groups. The incidence of nausea and vomiting was greater in the 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) groups than in the oxytocin (51%) group.

Prophylactic use of a combination of uterotonic medications did not lessen the requirement for further uterotonics during cesarean delivery for labor arrest when compared to oxytocin alone.