Membrane sweeping added to formal induction method to increase the spontaneous vaginal delivery: a meta-analysis

Membrane sweeping (MS) could increase the likelihood of spontaneous labor within 48 h. However, the rationale for performing routinely an intervention with the potential to induce labor in women with an uneventful pregnancy at 38 weeks of gestation is, at least, questionable. We conducted a meta-analysis of randomized controlled trial (RCT) studies to assess evaluated the effect of MS added to formal induction method on the spontaneous vaginal delivery, compared with formal induction alone.

PubMed, Embase, Cochrane Library databases, Web of Science, and Clinical Trials were searched from their inception to March 8, 2017. We estimate summarized relative risk (RR) and 95% confidence intervals (CIs) for dichotomous outcomes. The primary outcome was vaginal delivery, and second outcomes (side effects of MS) included meconium-stained liquor, admission to the neonatal unit, instrumental delivery.

Four RCTs with a total of 1377 participants were identified. The summary RR in the overall group was 1.12 (95% CI 1.05-1.18), with moderate heterogeneity (P = 0.22, I² = 33%). The summary RR in the nulliparas' subgroup was 1.32 (95% CI 1.18-1.48), with no heterogeneity (P = 0.79, I² = 0%). MS did not increase the risk of side effects.

MS added to formal induction significantly increased vaginal delivery rates, especially in nulliparas compared with formal induction alone. Notably, there are no obvious side effects of MS. Meanwhile, more RCTs studies are needed to investigate the side effects of MS on instrumental delivery, postpartum hemorrhage, and cervical laceration.