Carbetocin versus Oxytocin-Based Regimens in Macrosomic Births: A Comparative Hemodynamic Perspective

To compare the hemodynamic outcomes and blood loss parameters associated with carbetocin, oxytocin, and oxytocin–ergometrine regimens in isolated macrosomic pregnancies delivered via elective cesarean section. This retrospective cohort study included 336 term pregnancies with an fetal birth weight > 4000 g, delivered by elective cesarean section at Ankara Bilkent City Hospital between 2021 and 2023. Patients were stratified into three groups according to the uterotonic regimen received: carbetocin, oxytocin, or oxytocin–ergometrine. Demographic characteristics, hemoglobin changes, estimated blood loss (EBL), shock index, and need for surgical or medical interventions were analyzed. Multivariate linear regression was performed to assess independent predictors of EBL. Baseline characteristics were similar across groups. Carbetocin was associated with significantly lower EBL (524 ± 150 mL) compared to oxytocin (682 ± 175 mL) and oxytocin–ergometrine (706 ± 189 mL) (p = 0.037). Hemoglobin drop and shock index values were also more favorable in the carbetocin group. Carbetocin was associated with a lower incidence of both moderate and severe postpartum hemorrhage compared to oxytocin-based regimens in high-risk cesarean deliveries. Multivariate regression confirmed that carbetocin significantly reduced EBL independent of BMI and birth weight. Additionally, adverse effects such as nausea and vomiting were less frequent with carbetocin. Carbetocin demonstrates superior hemodynamic outcomes and lower blood loss compared to oxytocin-based regimens in macrosomic cesarean deliveries. Its use should be considered as a first-line uterotonic option in institutional protocols for such high-risk obstetric scenarios.