Carbetocin and peri-operative hemoglobin change at cesarean delivery in a setting of self-paid use: an 8-year retrospective cohort study.

backgroundPostpartum hemorrhage (PPH) is a leading cause of maternal morbidity, most often from uterine atony. Carbetocin, a long-acting heat-stable oxytocin analogue, reduces blood loss at cesarean delivery in randomized trials, but real-world data are sparse from settings where carbetocin is self-paid and not yet routine, such as Taiwan. We examined the association between carbetocin and peri-operative hemoglobin change at cesarean delivery in a setting of rising, patient-funded use.

methodsSingle-center retrospective cohort of deliveries between 2017 and 2025. Carbetocin (100 µg intravenously) was self-paid and chosen by the patient; comparators received the institutional standard (oxytocin alone at cesarean). The primary outcome was the peri-operative hemoglobin change (post- minus pre-delivery, g/dL) at cesarean delivery. Multivariable linear regression adjusted for age, BMI, parity, birth weight, and high-risk status, with calendar year added to address the secular trend in uptake; propensity-score inverse-probability weighting was a sensitivity analysis (complete-case). Because the recorded vaginal blood-loss field showed treatment-linked recording heterogeneity, only the binary PPH endpoint is reported for vaginal delivery.

resultsOf 6,266 deliveries with documented carbetocin status, 2,112 were cesarean. Among cesarean deliveries with paired peri-operative hemoglobin (carbetocin n = 734; no carbetocin n = 484; complete-case analytic n = 1,061), the median hemoglobin change was - 0.60 g/dL with carbetocin versus - 1.30 g/dL without; pre-delivery hemoglobin was identical between arms. The adjusted mean difference was + 0.79 g/dL (95% CI 0.65 to 0.94), consistent in low-risk (+ 0.84) and high-risk (+ 0.76) strata and under propensity weighting. A severe hemoglobin decline (≥ 2 g/dL) occurred in 11% versus 25% (supportive, sensitive to missing data). For vaginal delivery, PPH (≥ 500 mL) occurred in 3.2% versus 4.2% (year-adjusted odds ratio 0.68, 95% CI 0.46 to 1.01; not significant).

conclusionsIn this non-randomized, self-paid cohort, carbetocin was associated with a smaller peri-operative hemoglobin decline at cesarean delivery, directionally consistent with randomized evidence; the magnitude was larger than pooled trial estimates and is likely inflated by selection. Carbetocin was not associated with a lower incidence of PPH. Findings are associations and require cautious interpretation.

trial registrationNot applicable; this is a retrospective observational study and was not registered as a clinical trial.