Background Approximately 55 000 children are born in Norway each year. It is sometimes necessary to induce labour artificially. With respect to induction with drugs, misoprostol and dinoprostone are used irrespective of whether the cervix is mature or not, while oxytocin only is used when the cervix is mature. The Norwegian Board of Health Supervision asked The Norwegian Knowledge Centre for the health Services to systematically review the efficacy and safety of misoprostol for induction of labour.

Method This report is an overview of systematic reviews. We performed systematic searches in Cochrane Library, CRD and Ovid Medline and Embase. All included publications were evaluated for quality. In addition, we evaluated the quality of the evidence and the strength of recommendations for selected outcomes.

We also performed an evaluation of legal aspects regarding the use of misoprostol for induction of labour.

Results Five systematic reviews met our inclusion criteria. In the systematic reviews misoprostol was given vaginally, orally, sublingually or buccally. Misoprostol was used in different dosages and dosage intervals from study to study.

Our main findings were that vaginal and oral misoprostol was at least as effective as dinoprostone in inducing labour within 24 hours. However, it may have increased frequency of adverse events such as uterine hyperstimulation both without and with changes in fetal heart rate.

Conclusion It may appear that safety is more sensitive to the dose of misoprostol than efficacy. For sublingual and buccal administration of misoprostol the amount of data were limited and we were not able to conclude on efficacy and safety.