Oral misoprostol for induction of labour

Alfirevic Z, Weeks A

Published Online:

January 20, 2010

Oral misoprostol appears to be effective at inducing labour, but there is still not enough data to assess its safety.

Induction of labour (getting labour started artificially) is common when giving birth poses a lesser risk to the pregnant woman or her unborn child than continuing the pregnancy. Prostaglandins are hormones naturally present in the uterus (womb) that cause contractions in labour. Some prostaglandin products registered for use in pregnancy can be unstable at room temperature, and are expensive. Oral misoprostol, although only registered in a few countries for use in pregnancy, is a cheap and stable prostaglandin analogue, but high doses could be dangerous. This review of 56 trials (11,590 participants) found that oral misoprostol appears to be at least as effective as current methods of induction, and with lower caesarean section rates. Misoprostol appears to be safer when given orally than vaginally.

Abstract (click to read)

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). We updated this search on 21 September 2009 and added the results to the awaiting classification section.

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 OM with placebo (669 participants), women using OM were 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.

[Note: the 22 citations in the awaiting classification section of the review may alter the conclusions of the review once assessed.]

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.

Where misoprostol 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.

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

Assessed as up to date:

June 5, 2008

Find the research

Get full text at The Cochrane Library

Primary Review Group:

Pregnancy and Childbirth Group

Health topics:

Pregnancy & childbirth > Induction of labour > Techniques

Cochrane Summaries^beta

Independent high-quality evidence for health care decision making

Oral misoprostol for induction of labour

More like this

Copyright © 2012 - The Cochrane Collaboration