Carbetocin versus syntometrine for the third stage of labour following vaginal delivery-a double-blind randomised controlled trial

Objective Prevention of postpartum haemorrhage is essential in the pursuit of improved health care for women. However, limited literature is available for comparing the use of oxytocin agonist carbetocin with syntometrine in women undergoing vaginal deliveries. We aimed to compare intramuscular carbetocin with intramuscular syntometrine for the routine prevention of postpartum haemorrhage in women who deliver vaginally. Design Prospective double-blind randomised controlled trial. Setting Tertiary referral centre. Population Pregnant women with no contraindication for vaginal delivery recruited from January 2005 to April 2008. Methods Participants were randomised to receive either syntometrine or carbetocin during the third stage of labour. Main outcome measures Primary outcome measure was postpartum haemorrhage requiring additional uterotonics. Secondary outcome measures were the incidence of postpartum haemorrhage (>= 500 ml), severe postpartum haemorrhage (>= 1000 ml) and adverse effects profile. Results Women in the carbetocin group (13.5%) and in the syntometrine group (16.8%) had postpartum haemorrhage requiring additional uterotonics (P = 0.384). 1.6% of women in each group had postpartum haemorrhage (P = 1.0) and the estimated blood loss during the third stage of labour was similar between the two groups (P = 0.294). Women who had syntometrine were four times more likely to experience nausea (RR = 4.2; 95% CI 2.2-7.8) and vomiting (RR = 4.3; 95% CI 1.9-9.5) compared with women who had carbetocin. Tremor, sweating, retching and uterine pain were also more likely in the syntometrine group compared with the carbetocin group (P < 0.05). Conclusions Carbetocin has an efficacy similar to syntometrine for prevention of postpartum haemorrhage, but is associated with less adverse effects.