STUDY DESIGN: Participants were randomized to intravenous bolus injection of 100mcg carbetocin or 10IU oxytocin after cesarean delivery of the baby. The primary outcome is any additional uterotonic which may be administered by the blinded provider for perceived inadequate uterine tone with or without hemorrhage in the first 24hours after delivery. Secondary outcomes include operating time, perioperative blood loss, change in hemoglobin and hematocrit levels, blood transfusion and reoperation for postpartum hemorrhage.
RESULTS: Additional uterotonic rates were 107/276 (38.8%) vs. 155/271 (57.2%) [RR 0.68 95% CI 0.57-0.81 p<0.001; NNTb 6 95% CI 3.8-9.8], mean operating time 45.9±16.0 vs. 44.5±13.1minutes p=0.26, mean blood loss 458±258 vs. 446±281ml p=0.6, severe postpartum hemorrhage (≥1000ml) rates 15/276 (5.4%) vs. 10/271 (3.7%) p=0.33 and blood transfusion rates 6/276 (2.2%) vs. 10/271 (3.7%); p=0.30 for carbetocin and oxytocin arms respectively. There was only one case of re-operation (oxytocin arm). In the cases that needed additional uterotonic 98% (257/262) was started intraoperatively and in 89% (234/262) the only additional uterotonic administered was an oxytocin infusion over 6hours.
CONCLUSION: Fewer women in the carbetocin arm needed additional uterotonics but perioperative blood loss, severe postpartum hemorrhage, blood transfusion and operating time were not different.
MATERIALS AND METHODS: Major electronic databases were searched for randomized-controlled trials comparing carbetocin with oxytocin. Only trials involving cesarean deliveries were included. Non-randomized trials, non-cesarean deliveries, studies which did not directly compare carbetocin to oxytocin and studies which did not analyze the intended outcomes were excluded. Outcomes analysed were postpartum hemorrhage, additional use of uterotonic and transfusion requirement.
RESULTS: Seven studies involving 2012 patients were included in the meta-analysis. There was a significant reduction in the rates of postpartum hemorrhage (RR 0.79; 95% CI 0.66 to 0.94; p = 0.009), use of additional uterotonics (RR 0.57; 95% CI 0.49 to 0.65; p oxytocin was used. There was significant heterogeneity across studies however, for the outcome of additional uterotonic usage.
CONCLUSION: Carbetocin is effective in reducing the use of additional uterotonics, reduction in postpartum hemorrhage and transfusion when used during cesarean deliveries. However, despite the potential benefits illustrated in this meta-analysis, the disparity between the cost of carbetocin and oxytocin suggests that locoregional cost-effectiveness analysis should be performed before any decision is made to adopt it for routine prophylaxis.