Fourteen RCTs (n=2,172) were included.
All of the studies reported randomisation. Twelve studies reported the methods used for randomisation, and the majority of these used opaque, sealed envelopes in an attempt to conceal treatment allocation. Two studies did not report either the randomisation method or if allocation was concealed. One study reported blinding of the patient and the delivering physician.
Any misoprostol versus any PgE2.
There was no significant difference between any misoprostol and any PgE2 in the rate of Caesarean section delivery (RR 0.99, 95% CI: 0.83, 1.17).
Any misoprostol was associated with a significantly higher risk of tachysystole (RR 1.86, 95% CI: 1.01, 3.43) and hyperstimulation (RR 3.71, 95% CI: 2.00, 6.88) compared with PgE2.
Among all vaginal deliveries, misoprostol was associated with a higher rate of vaginal delivery within 24 hours than PgE2 (RR 1.14, 95% CI: 1.00, 1.31).
Among all deliveries, misoprostol was associated with a significantly lower rate of oxytocin use (RR 0.71, 95% CI: 0.60, 0.85) compared with PgE2, but a non significant increase in meconium staining (RR 1.22, 95% CI: 0.96, 1.55).
The results were similar when the analysis was restricted to misoprostol starting doses of more than 25 microg. Studies evaluating starting doses of misoprostol of 25 microg showed no significant differences in outcomes between misoprostol and PgE2, but the authors reported that the analyses might have been underpowered (n=304).
For nulliparous women (3 RCTs, n=348), there was no significant difference between any misoprostol and any PgE2 in the risk of Caesarean section or hyperstimulation, but misoprostol was associated with an increased risk of tachysystole (RR 2.68, 95% CI: 1.14, 6.29).
Oral and vaginal misoprostol versus any PgE2.
There were no significant differences in the rate of Caesarean section or tachysystole between oral or vaginal misoprostol and any PgE2.
Vaginal misoprostol was associated with a significantly increased risk of hyperstimulation compared with any PgE2 (RR 3.80, 95% CI: 1.91, 7.58).
Any misoprostol versus vaginal and IC PgE2.
There were no significant differences in the rate of Caesarean section between any misoprostol and either vaginal or IC PgE2.
Any misoprostol was associated with a significantly increased risk of tachysystole compared with IC PgE2 (RR 8.32, 95% CI: 2.27, 30.55), but not compared with vaginal PgE2.
Hyperstimulation was significantly more common with any misoprostol compared with both vaginal PgE2 (RR 2.99, 95% CI: 1.25, 7.16) and IC PgE2 (RR 4.61, 95% CI: 1.91, 11.09).
The results for the other outcomes were also reported.