Mechanical methods for induction of labour
Cochrane Database of Systematic Reviews, 2011
Publication History Publication Status: New search for studies and content updated (conclusions changed) Published Online: 14 MAR 2012 SEARCH ARTICLE TOOLS Abstract Abstract Background Mechanical methods were the first methods developed to ripen the cervix and induce labour.
Potential advantages of mechanical methods, compared with pharmacological methods, may include simplicity of preservation, lower cost and reduction of the side effects.
Objectives To determine the effects of mechanical methods for third trimester cervical ripening or induction of labour in comparison with placebo/no treatment, prostaglandins (vaginal and intracervical prostaglandin E2 (PGE2), misoprostol) and oxytocin.
Search methods We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2011) and bibliographies of relevant papers.
We updated this search on 16 January 2012 and added the results to the awaiting classification section of the review.
Selection criteria Clinical trials comparing mechanical methods used for third trimester cervical ripening or labour induction with methods listed above it on a predefined list of methods of labour.
Different types of intervention have been considered as mechanical methods: (1) introduction of laminaria tents, or their synthetic equivalent (Dilapan), into the cervical canal; (2) the introduction of a catheter through the cervix into the extra-amniotic space, with or without traction; (3) use of a catheter to inject fluidsin the extra-amniotic space In addition, we made other comparisons: (1) specific mechanical methods (balloon catheter and laminaria tents) compared with any prostaglandins or with oxytocin; (2) addition of prostaglandins or oxytocin to mechanical methods compared with prostaglandins alone.
Data collection and analysis Two review authors independently assessed trials for inclusion and assessed risk of bias.
The review includes 71 randomised controlled trials (total of 9722 women), ranging from 39 to 588 women per study.
Most studies reported on caesarean section, all other outcomes are based on substantially fewer women.
Mechanical methods versus no treatment: one study (48 woman) reported on women who did not achieve vaginal delivery within 24 hours (risk ratio (RR) 0.90; 95% confidence interval (CI) 0.64 to 1.26).