Twenty-two RCTs (n=30,017) were included in the review.
The quality assessment scores ranged from 5 to 9, with most studies scoring 7 or 8.
Misoprostol versus placebo.
Four trials that compared misoprostol with placebo and reported results for blood loss of 1,000 mL or more and one trial that reported results for blood loss of 500 mL or more were pooled. There was no statistically significant difference between the misoprostol and placebo groups (RR 0.85, 95% confidence interval, CI: 0.63, 1.14). There was no significant heterogeneity.
Patients given placebo were statistically significantly more likely to require additional uterotonic agents than those given misoprostol (4 trials; RR 0.69, 95% CI: 0.53, 0.90).
Misoprostol versus oxytocics.
Blood loss of 500 mL or more was statistically significantly greater in the misoprostol group than in the oxytocics group (15 trials; RR 1.40, 95% CI: 1.21, 1.62), representing an excess risk of 5% greater incidence of blood loss. There was slight heterogeneity across the studies; however, the fixed-effect and random-effects estimates were similar.
Blood loss of 1,000 mL or more was also statistically significantly greater in the misoprostol group than in the oxytocics group (11 trials; RR 1.36, 95% CI: 1.19, 1.56), representing an excess risk of 1% greater incidence of severe PPH.
There was no statistically significant difference in the requirement for additional uterotonic agents between patients in the misoprostol group and those in the oxytocics group (17 trials; RR 1.23, 95% CI: 0.93, 1.63). A subgroup analysis of oral and sublingual misoprostol also revealed no statistically significant difference between misoprostol and oxytocics (RR 1.13, 95% CI: 0.81, 1.56).
There was no evidence of significant publication bias for any outcome.