Treatment of post-partum haemorrhage with sublingual misoprostol versus oxytocin in women not exposed to oxytocin during labour: a double-blind, randomised, non-inferiority trial

Abstract

Background: Oxytocin, the standard of care for treatment of post-partum haemorrhage, is not available in all settings because of refrigeration requirements and the need for intravenous administration. Misoprostol, an effective uterotonic agent with several advantages for resource-poor settings, has been investigated as an alternative. This trial established whether sublingual misoprostol was similarly efficacious to intravenous oxytocin for treatment of post-partum haemorrhage in women not exposed to oxytocin during labour.

Methods: In this double-blind, non-inferiority trial, 9348 women not exposed to prophylactic oxytocin had blood loss measured after vaginal delivery at four hospitals in Ecuador, Egypt, and Vietnam (one secondary-level and three tertiary-level facilities). 978 (10%) women were diagnosed with primary post-partum haemorrhage and were randomly assigned to receive 800 microg misoprostol (n=488) or 40 IU intravenous oxytocin (n=490). Providers and women were masked to treatment assignment. Primary endpoints were cessation of active bleeding within 20 min and additional blood loss of 300 mL or more after treatment. Clinical equivalence of misoprostol would be accepted if the upper bound of the 97.5% CI fell below the predefined non-inferiority margin of 6%. All outcomes were assessed from the time of initial treatment. This study is registered with ClinicalTrials.gov, number NCT00116350.

Findings: All randomly assigned participants were analysed. Active bleeding was controlled within 20 min with study treatment alone for 440 (90%) women given misoprostol and 468 (96%) given oxytocin (relative risk [RR] 0.94, 95% CI 0.91-0.98; crude difference 5.3%, 95% CI 2.6-8.6). Additional blood loss of 300 mL or greater after treatment occurred for 147 (30%) of women receiving misoprostol and 83 (17%) receiving oxytocin (RR 1.78, 95% CI 1.40-2.26). Shivering (229 [47%] vs 82 [17%]; RR 2.80, 95% CI 2.25-3.49) and fever (217 [44%] vs 27 [6%]; 8.07, 5.52-11.8) were significantly more common with misoprostol than with oxytocin. No women had hysterectomies or died.

Interpretation: In settings in which use of oxytocin is not feasible, misoprostol might be a suitable first-line treatment alternative for post-partum haemorrhage.