A network meta-analysis 2 assessed the relative effectiveness, safety and cost-effectiveness of labour induction methods. 611 trials were included. The interventions most likely to achieve vaginal delivery within 24 hours were intravenous oxytocin with amniotomy (posterior rank 2; 95% credible intervals (CI) 1 to 9) and higher-dose (≥ 50 µg) vaginal misoprostol (rank 3; 95% CI 1 to 6) (table T1). Compared with placebo, several treatments reduced the odds of caesarean section, but there were considerable uncertainty in treatment rankings. For uterine hyperstimulation, double-balloon catheter had the highest probability of being among the best 3 treatments, whereas vaginal misoprostol (≥ 50 µg) was most likely to increase the odds of excessive uterine activity.
| Active intervention vs placebo | Odds ratio | 95% CI |
|---|---|---|
| i.v. oxytocin with amniotomy | 0.05 | 0.07 to 0.32 |
| Vaginal misoprostol ≥ 50 μg | 0.09 | 0.06 to 0.24 |
| Titrated (low-dose) oral misoprostol solution | 0.10 | 0.07 to 0.29 |
| Vaginal misoprostol < 50 μg | 0.11 | 0.09 to 0.32 |
| Buccal/sublingual misoprostol | 0.11 | 0.05 to 0.19 |
| Vaginal PGE2 pessary (normal release) | 0.11 | 0.04 to 0.16 |
| Vaginal PGE2 (gel) | 0.13 | 0.08 to 0.50 |
| Vaginal PGE2 pessary (slow release) | 0.15 | 0.08 to 0.29 |
| Vaginal PGE2 (tablet) | 0.16 | 0.03 to 0.26 |
| Intracervical PGE2 | 0.18 | 0.09 to 0.38 |
A Cochrane review [Abstract] 1 included 70 studies with a total of 11 487 women. Overall vaginal PGE2 (tablets, gels and pessaries including sustained release preparations) compared with placebo or no treatment non-significantly reduced the rate of unsuccessful vaginal delivery within 24 hours (RR 0.32, 95% CI 0.02 to 4.83; 2 trials, n=384). The risk of the cervix remaining unfavourable or unchanged was reduced (RR 0.41, 95% CI 0.27 to 0.65; 6 trials, n=567).There was a trend for lower caesarean section rates (RR 0.91, 95% CI 0.81 to 1.02; 36 trials, n=6599) although the risk of uterine hyperstimulation with fetal heart rate changes was increased (RR 3.16, 95% CI 1.67 to 5.98; 15 trials, n=1359).
PGE2 tablet, gel and pessary appear to be equally effective.
Primary/Secondary Keywords