Carbetocin and Oxytocin Show Non-Significant Differences in Preventing Postpartum Hemorrhage After Emergency C-sections

Postpartum hemorrhage (PPH) remains a leading cause of maternal morbidity and mortality globally, with cesarean delivery carrying a higher risk of blood loss compared to vaginal birth. Current prophylactic strategies primarily rely on oxytocin, a uterotonic agent that stimulates uterine contractions to prevent excessive bleeding. However, oxytocin has a relatively short half-life, necessitating continuous infusion or repeat dosing in some cases. Carbetocin, a synthetic analog of oxytocin with a longer half-life, has been investigated as a potentially more effective or convenient alternative, particularly in high-risk scenarios, but its comparative efficacy in antenatally low-risk women undergoing emergency C-sections requires further evaluation.

This prospective observational, non-randomized comparative study enrolled 300 antenatally low-risk women requiring NICE Category 1-2 emergency cesarean delivery. Participants received either oxytocin 10 IU intravenous (IV) or carbetocin 100 µg IV immediately post-delivery. The primary outcome was any additional uterotonic use within 24 hours. Secondary outcomes included tranexamic acid use, hemoglobin decrease ≥ 2 g/dL at 24 hours, absolute hemoglobin change (ΔHb), and postoperative hemoglobin < 8 g/dL. Multivariable logistic regression was performed to identify factors associated with additional uterotonic use.

A total of 300 women were included, with 150 in each treatment group. Additional uterotonic use occurred in 24.0% (36/150) of the carbetocin group and 33.3% (50/150) of the oxytocin group, a difference that was not statistically significant (p=0.074). Tranexamic acid use also did not differ significantly between groups (18.7% vs. 16.0%, p=0.542). Hemoglobin decrease ≥ 2 g/dL occurred in 68.0% (carbetocin) and 60.0% (oxytocin), respectively (p=0.149). Mean ΔHb was 2.49 ± 1.13 g/dL in the carbetocin group and 2.38 ± 1.03 g/dL in the oxytocin group (p=0.388). Postoperative hemoglobin < 8 g/dL was observed in 11.3% and 12.0% of patients, respectively (p=0.981).