Objective: To compare the effect of 400 mu g of oral misoprostol with 5 U of intravenous oxytocin in the reduction of postpartum blood loss and prevention of postpartum hemorrhage. Methods: In a prospective, double-blind, randomized controlled trial conducted in a tertiary maternity hospital 622 women received either 400 mu g of oral misoprostot or 5 U of intravenous oxytocin after delivery of the anterior shoulder orwithin 1 min of delivery. The primary outcome was a hematocrit drop of 10% or greater 24 In postpartum. The secondary outcomes were a hemoglobin drop of 30 mg/L or greater, the use of additional oxytocin, an estimated blood toss greater than 1000 mL, manual removal of the placenta, a blood transfusion, and shivering and fever (>= 38 degrees C) its adverse effects of misoprostol. Results: There was no difference between the 2 groups regarding the primary outcome (a >= 10% hematocrit drop occurred in 3.4% and 3.7% of the participants in the oxytocin and misoprostol groups, P=0.98). The rate of use of additional oxytocinwas higherin the misoprostol group (51% versus 40.5%, P=0.01). Shivering was confined to the misoprostoL group (6.8%), and fever occurred in 12.5% of the women in the misoprostol group and 0.3% of the women in the oxytocin group. Conclusion: The routine use of 400 mu g of oral misoprostot was no less effective than 5 U of intravenous oxytocin in reducing blood loss after delivery, as assessed by change in postpartum hematocrit. The adverse effects of misoprostot were mild and self-limiting. (c) 2007 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.