Effectiveness and safety of membrane sweeping in the prevention of post-term pregnancy: a randomised controlled trial.

There is a rising concern with increasing rates of pharmacologically induced labour and its complications. Membrane sweeping is a simple and less invasive means of initiating spontaneous labour onset. We compared the safety and efficacy of membrane sweeping. A total of 186 women (62 in each arm) were recruited at the antenatal clinic at 39 weeks. The intervention groups had membrane sweeping once and twice weekly respectively while the control arm had no membrane sweeping. They were all monitored and followed up till delivery. The trial was registered with the South Africa registry www.pactr.org (PACTR202112841108933) The incidence of prolonged pregnancy was 32.3%, 19.4% and 11.7% among the control, once-weekly, and twice-weekly groups respectively. The sweeping to the delivery interval was significantly shorter for the twice-weekly group (7.4 days) compared to once weekly (8.8 days) and the control group (10.6 days). There were significantly higher odds of spontaneous labour onset in the twice-weekly group (HR 1.53,  = .029) compared to the control group (HR 0.65,  = .033) and the once-weekly group using once weekly as reference. Membrane sweeping is a safe and effective means of preventing prolonged pregnancy. Twice-weekly sweeping of foetal membranes is more effective than once-weekly or no sweeping without added adverse feto-maternal outcomes.IMPACT STATEMENT 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 so as to initiate spontaneous labour onset. Membrane sweeping twice weekly after 39weeks for low-risk pregnant women is more effective than once weekly or no sweep with no added adverse maternal or perinatal risks. Twice-weekly membrane sweeping is encouraged in selected patients to reduce the risks associated with post-term pregnancy.