Amniotomy for induction of labour

Evidence Summaries

Level of Evidence = A
Amniotomy with i.v. oxytocin is effective for induction of labour compared with placebo.

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.


Table 1. Interventions for failure to achieve vaginal delivery within 24 hours
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
Oral misoprostol tablet ≥ 50 μg 0.16 0.05 to 0.20
Double-balloon or Cook’s catheter 0.18 0.01 to 0.16
Foley catheter 0.19 0.09 to 0.46
Oral misoprostol tablet < 50 μg 0.22 0.07 to 0.39

A Cochrane review 1 included 2 studies with a total of 310 subjects. No conclusions could be drawn from comparisons of amniotomy alone versus no intervention, or amniotomy alone versus oxytocin alone. One trial compared amniotomy alone with a single dose of vaginal prostaglandins for women with a favourable cervix, and found a significant increase in he need for oxytocin augmentation in the amniotomy alone group (44% versus 15%, RR 2.85, 95% CI 1.82 to 4.46).

References

1. Bricker L, Luckas M. Amniotomy alone for induction of labour. Cochrane Database Syst Rev 2000;(4):CD002862 [Review content assessed as up-to-date: 31 January 2007].  [PMID:11034776]
2. Alfirevic Z, Keeney E, Dowswell T et al. Which method is best for the induction of labour? A systematic review, network meta-analysis and cost-effectiveness analysis. Health Technol Assess 2016;20(65):1-584.  [PMID:27587290]

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