Nine studies included in review (n=3,344 calculated from tables in paper and n=2,937 reported in paper, range 30 to 741 participants). Three achieved the maximum Jadad quality score of 5 points; six achieved 3 points.
Comparison between oral misoprostol and dinoprostone: There was a statistically significant reduction in the risk of women who required caesarean section in women who received oral misoprostol (RR 0.82, 95% CI 0.71 to 0.96, I2=6%; five studies). There were no statistically significant differences for all other primary and secondary outcomes.
Comparison between oral and vaginal misoprostol: There was a statistically significant difference in the rates of the primary outcome uterine hyperstimulation with foetal heart rate changes (RR 0.19, 95% CI 0.08 to 0.46, I2=48%; two studies) that favoured oral over vaginal misoprostol. This was also true for the secondary outcome uterine hyperstimulation without foetal heart rate changes (RR 0.36, 95% CI 0.22 to 0.59, I2=0%; two studies). No statistically significant differences were reported for all other outcomes. Maternal outcome results were not reported.
No statistically significant differences were reported between groups in the two studies that compared oral misoprostol with oxytocin therapy.
Heterogeneity assessed with the I2 statistic varied between 0% and 92%. For all of the statistically significant outcomes I2 was under 50%, and so judged not to be significant.
No studies had a quality score of less than 3 out of 5, so a planned sensitivity analysis to investigate heterogeneity that stratifying results by study quality was not conducted.