Oral misoprostol for induction of labour

Cochrane Review by Alfirevic Z, Weeks A

This record should be cited as: Alfirevic Z, Weeks A. Oral misoprostol for induction of labour. Cochrane Database of Systematic Reviews 2006, Issue 2. Art. No.: CD001338. DOI: 10.1002/14651858.CD001338.pub2.

ABSTRACT

Title

Oral misoprostol for induction of labour

Background

Misoprostol is an orally active prostaglandin. In most countries misoprostol is not licensed for labour induction, but its use is common because it is cheap and heat stable.

Objectives

To assess the use of oral misoprostol (OM) for labour induction in women with a viable fetus.

Search strategy

We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (May 2008).

Selection criteria

Randomised trials comparing OM versus placebo or other methods, given to women with a viable fetus for labour induction.

Data collection and analysis

Two review authors independently assessed trial data, using centrally-designed data sheets.

Main results

In seven trials comparing OMwith placebo (669 participants), women using OMwere more likely to deliver vaginally within 24 hours (risk ratio (RR) 0.16, 95% confidence interval (CI) 0.05 to 0.49), needed less oxytocin (RR 0.35, 95% CI 0.28 to 0.44) and had a lower caesarean section rate (RR 0.61, 95% CI 0.41 to 0.93). In ten trials comparing OM with vaginal dinoprostone (3368 participants), women given OM were less likely to need a caesarean section (RR 0.87, 95% CI 0.77 to 0.98). There was some evidence that they had slower inductions, but there were no other significant differences. Eight trials (1026 participants) compared OM with intravenous oxytocin. The only difference was an increase in meconium-stained liquor in women with ruptured membranes with OM (RR 1.72, 95% CI 1.08 to 2.74). Twenty-six trials (5096 participants) compared oral and vaginal misoprostol and found no difference in the primary outcomes. However there were fewer babies born with a low Apgar score in the OM group (RR 0.65, 95% CI 0.44 to 0.97). There was evidence of less uterine hyperstimulation with OM, but heterogeneity makes these outcomes difficult to interpret.

Authors' conclusions

OM as an induction agent is effective at achieving vaginal delivery. It is more effective than placebo, as effective as vaginal misoprostol and results in fewer caesarean sections than vaginal dinoprostone. Wheremisoprostol remains unlicenced for the induction of labour,many practitioners will prefer the legal protection of using a licenced product like dinoprostone. If using OM, clinicians should use a dose of 20 to 25 mcg in solution. Given that safety is the primary concern, the oral regimens are recommended over vaginal regimens. This is especially important in situations where the risk of ascending infection is high and the lack of staff means that women cannot be intensely monitored.