Membrane sweeping at term to promote spontaneous labour and reduce the likelihood of a formal induction of labour for postmaturity: a systematic review and meta-analysis

Abstract

The aim of this study was to evaluate the efficacy and the safety of membrane sweeping in promoting spontaneous labour and reducing a formal induction of labour for postmaturity. Based on articles published between 2005 and 2016, 12 electronic databases were searched. Relative risk (RR) and its 95% confidence interval (CI) were used as pooled statistics. A total of seven studies consisting of 2252 participants were selected for the review and meta-analysis. The results revealed that membrane sweeping is advantageous in promoting spontaneous labour (RR = 1.205, 95% CI: 1.133-1.282, p = <.001), and reducing the formal induction of labour for postmaturity (RR = 0.523, 95% CI: 0.409-0.669, p = <.001). The studies reported several varying outcomes for both maternal and foetal morbidities; meta-analyses were performed where possible on each of these and found there to be no statistically significant differences in outcome between the intervention and control groups. Impact Statement What is already known on this subject? Research suggests that a pregnancy which exceeds 42 weeks of gestation is associated with an increased risk of perinatal morbidity and mortality (Gulmezoglu et al. 2012 ). Consequently, a formal induction of labour is usually offered to low-risk pregnant women between 41 and 42 weeks of pregnancy. However, all of the induction methods carry some degree of risk in terms of the associated morbidities and effectiveness (Cunningham 2005 ; Simpson and James 2008 ; Thomas et al. 2014 ), as well as having an impact on NHS resources (Department of Health 2015 ), and the birth experience of women (Gatward et al. 2010 ). For these reasons, it is currently recommended by The National Institute for Health and Care Excellence (NICE 2008 ) that women are offered a membrane sweep to promote spontaneous labour prior to arranging a formal induction of labour. What the results of this study add? The results from this meta-analysis add to the body of existing evidence around membrane sweeping. This study clearly demonstrates that membrane sweeping is effective in promoting a spontaneous labour and thereby reducing the need for a formal induction of labour. However, the results of this review suggest that this effect is significant from 38 weeks of gestation, and is not dependent upon the number or timing of membrane sweeps performed. What the implications are of these findings for clinical practice and/or further research? There is no evidence supporting any increase in maternal or foetal morbidity suggesting that membrane sweeping is a safe procedure to offer to all low risk pregnant women. We recommend therefore that there could be a reduction in the gestation at which membrane sweeping is offered from 40 weeks for primiparous women and 41 weeks for multiparous women to 38 weeks onwards for all low risk women without any increased risk of maternal or foetal morbidity. This may result in a decreased risk of requiring a formal induction of labour for postmaturity.

Keywords: Term pregnancy; membrane stripping; membrane sweeping; post-dates pregnancy; postmaturity; stretch and sweep.