Clinical and financial evaluation of carbetocin as postpartum haemorrhage prophylaxis at caesarean section: A retrospective cohort study

Background: The long-acting oxytocic agent; carbetocin, has been consistently shown to reduce the need for additional uterotonics at caesarean section, but not postpartum haemorrhage (PPH). While promising, current evidence is limited by heterogenicity in study design and findings.

Aims: To examine whether carbetocin confers clinical or economic benefit compared to oxytocin at caesarean section in an all-risk Australian population.

Materials and methods: A retrospective cohort study was undertaken of all singleton caesarean sections at a public tertiary hospital from 2008 to 2010 (n = 2499). From 1 January 2008 to 24 March 2009 all women received prophylactic oxytocin 5-10 units slow push intravenously at delivery, after which all patients received 100 μg intravenous carbetocin. Outcomes were PPH (≥1000 mL) and the requirement of secondary uterotonics. A post hoc cost analysis was also performed.

Results: A total of 1467 and 1024 patients received carbetocin and oxytocin, respectively. Incidence of PPH ≥1000 mL was 7.8% for carbetocin compared to and 9.7% for oxytocin (odds ratio (OR) 0.79, 95% CI 0.59-1.05). Moderate blood loss >500 mL was significantly reduced with carbetocin; occurring in 27.3% versus 39.4% (OR 0.57, 95% CI 0.49-0.68). There was a 20.0% reduction in secondary uterotonic treatment with carbetocin (OR 0.42, 95% CI 0.35-0.49). Average drug costs were lower with oxytocin at $4.74 versus $36.42/patient. However, the 1.9% reduction in PPH with carbetocin resulted in a $63.46 reduction in cost per patient, with a cost-effectiveness ratio of $1667 to prevent one case of PPH ≥1000 mL.

Conclusions: Carbetocin reduced moderate blood loss >500 mL, but not PPH ≥1000 mL. Carbetocin conferred a 20% reduction in secondary uterotonic treatment, as well as lowering direct medical costs.