Oral prostaglandin E2 for induction of labour

Oral prostaglandin E2 is no more effective than other methods of induction but has more adverse effects.

Induction of labour is sometimes considered beneficial in some clinical circumstances, e.g., when the baby is not growing properly, when there is pre-eclampsia or when gestation goes beyond the normal length of pregnancy. There are many varying methods used to try to stimulate labour including administration of drugs, mechanical methods such as sweeping of the membranes, and more natural methods like nipple stimulation and having sex. Care needs to be taken to balance the stimulation of labour without over-stimulating and causing the baby difficulties. Prostaglandin E2 (PGE2) is a hormone given either by mouth or by insertion through the vagina to prepare and stimulate the cervix and bring on labour. This review looked at oral PGE2 compared with no intervention, and compared with several other methods of induction. The review identified 19 studies involving 2688 women, looking at eight differing comparisons. The review found that none of the trials assessed the effectiveness of oral PGE2 in inducing labour, but overall the trials found that PGE2 caused more frequent gastrointestinal adverse effects, particularly vomiting. There were no clear advantages to oral PGE2 over other methods used to bring on labour, except that women may prefer a method that does not require an intravenous infusion. Over stimulation of the baby may possibly be a possible problem with PGE2, but the increased incidence of gastrointestinal side-effects do not favor its use.

Authors' conclusions: 

Oral prostaglandin consistently resulted in more frequent gastrointestinal side-effects, in particular vomiting, compared with the other treatments included in this review. There were no clear advantages to oral prostaglandin over other methods of induction of labour.

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

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Background: 

This is one of a series of reviews of methods of cervical ripening and labour induction using standardized methodology.

Objectives: 

To determine the effects of oral prostaglandin E2 for third trimester induction of labour.

Search strategy: 

The Cochrane Pregnancy and Childbirth Group's Trials Register (January 2007) and bibliographies of relevant papers. We updated this search on 8 June 2012 and added the results to the awaiting classification section of the review.

Selection criteria: 

Clinical trials comparing oral prostaglandin E2 used for third trimester cervical ripening or labour induction with placebo or no treatment or other methods listed above it on a predefined list of labour induction methods.

Data collection and analysis: 

A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction.

Main results: 

There were 19 studies included in the review. Of these 15 included a comparison using either oral or intravenous oxytocin with or without amniotomy. The quality of studies reviewed was not high. Only seven studies had clearly described allocation concealment. Only two studies stated that providers or participants, or both, were blinded to treatment group.

For the outcome of vaginal delivery not achieved within 24 hours, in the composite comparison of oral PGE2 versus all oxytocin treatments (oral and intravenous, with and without amniotomy), there was a trend favoring oxytocin treatments (relative risk (RR) 1.97, 95% confidence interval (CI) 0.86 to 4.48).

For the outcome of cesarean section, in the comparison of PGE2 versus no treatment or placebo, PGE2 was favored (RR 0.54, 95% CI 0.29 to 0.98). Otherwise, there were no significant differences between groups for this outcome.

Oral prostaglandin was associated with vomiting across all comparison groups.