Objective: To evaluate the effectiveness of sweeping of the membranes to prevent post-term pregnancy and to induce labour.
Design: A systematic review of randomised controlled trials.
Methods: Potentially eligible trials were identified in Medline and in the Cochrane Controlled Trials Register. Inclusion of studies and data extraction were performed by two reviewers working independently. Summary estimates of the effect of the intervention were computed as relative risks, risk differences and weighted mean differences.
Main outcome measures: Use of formal methods of labour induction, delay before spontaneous onset of labour, prevention of post-term pregnancy, side effects, maternal and perinatal morbidity.
Results: Sixteen reports were identified. Thirteen were included in the review, with a total of 1992 women. Sweeping of the membranes, when performed at term, reduced the duration of pregnancy and the proportion of women continuing pregnancy beyond 41 and 42 weeks. When sweeping of the membranes was performed, a reduction in the use of formal methods for labour induction was observed (RR = 0.48; 95% CI 0.28-0.85). There was no difference between groups in the mode of delivery or in the risk of infection. Discomfort during vaginal examination and other side effects (e.g. bleeding, irregular contractions) were more frequently reported by women allocated to sweeping.
Conclusions: While sweeping of the membranes reduces the interval to spontaneous onset of labour, there is no evidence of a reduction in maternal or neonatal morbidity. When used as a means of induction of labour, the reduction in the use of formal methods must be balanced against women's discomfort and other side effects attributable to the procedure.