Carbetocin versus oxytocin for the prevention of postpartum haemorrhage following caesarean section: the results of a double-blind randomised trial.

OBJECTIVE: To compare the effectiveness of carbetocin and oxytocin when they are administered after caesarean section for prevention of postpartum haemorrhage (PPH).

STUDY DESIGN: Double-blind randomised single centre study (1:1 ratio).

SETTING: Teaching hospital in Bristol, UK with 6000 deliveries per annum.

POPULATION: Women at term undergoing elective or emergency caesarean section under regional anaesthesia, excluding women with placenta praevia, multiple gestation and placental abruption.

METHODS: Women were randomised to receive either carbetocin 100 microg or oxytocin 5 IU intravenously after the delivery of the baby. Perioperative care was otherwise normal and use of additional oxytocics was at the discretion of the operating obstetrician. Analysis was by intention to treat.

PRIMARY OUTCOME MEASURE: The proportion of women in each arm of the trial that needed additional pharmacological oxytocic interventions.

RESULTS: Significantly more women needed additional oxytocics in the oxytocin group (45.5% versus 33.5%, Relative risk 0.74, 95% CI 0.57-0.95). The majority of women had oxytocin infusions. There were no significant differences in the secondary outcomes, including major PPH, blood transfusions and fall in haemoglobin.

CONCLUSIONS: Carbetocin is associated with a reduced use of additional oxytocics. It is unclear whether this may reduce rates of PPH and blood transfusions.