Carbetocin compared with oxytocin in non-elective Cesarean delivery: a systematic review, meta-analysis, and trial sequential analysis of randomized-controlled trials

Purpose: Carbetocin has been shown to reduce the requirement for additional uterotonics in women exclusively undergoing elective Cesarean delivery (CD). The aim of this review was to determine whether this effect could also be demonstrated in the setting of non-elective CD. Methods: Medline, Embase, CINAHL, Web of Science and Cochrane databases were searched for randomized-controlled trials (RCTs) in any language comparing carbetocin to oxytocin. Studies with data on women undergoing non-elective CD, where carbetocin was compared with oxytocin, were included. The primary outcome was the need for additional uterotonics. Secondary outcomes included incidence of blood transfusion, estimated blood loss (mL), incidence of postpartum hemorrhage (PPH; > 1000 mL) and mean hemoglobin drop (g·dL⁻¹ Results: Five RCTs were included, with a total of 1,214 patients. The need for additional uterotonics was reduced with carbetocin compared with oxytocin (odds ratio, 0.30; 95% CI, 0.11 to 0.86; I², 90.60%). Trial sequential analysis (TSA) confirmed that the information size needed to show a significant reduction in the need for additional uterotonics had been exceeded. No significant differences were shown with respect to any of the secondary outcomes, but there was significant heterogeneity between the studies. Conclusions: Carbetocin reduces the need for additional uterotonics in non-elective CD compared with oxytocin. TSA confirmed that this analysis was appropriately powered to detect the pooled estimated effect. Further trials utilizing consistent core outcomes are needed to determine an effect on PPH. Trial registration: PROSPERO CRD42019147256, registered 13 September 2019.