Membrane Sweeping (Stretch and Sweep): Cochrane Review (Finucane et al., 2020)

A membrane sweep, or stretch and sweep, is performed when a clinician inserts a finger through the cervix and separates the membranes from the lower uterus. The idea is to release hormones that nudge the body into starting on its own. It requires a vaginal exam and is offered at term, usually from 39 to 41 weeks. Before term there is no evidence it helps, because every trial was run at or near term. The Cochrane review (Finucane et al., 2020) pools 44 trials and 6,940 women.

The effect is small. Slightly more women start spontaneously, and the share needing a formal induction drops from about 313 to 228 per 1,000. That means roughly 12 women have to be swept for one to avoid an induction. After that the benefit runs out. C-section rates do not change, the spontaneous vaginal birth rate is flat, and nothing in the data shows the baby does better. The reviewers rate the evidence low, and moderate for cesareans.

The downsides are the part nobody mentions first. In one trial half the women called the procedure somewhat painful and one in six called it painful or very painful. Bleeding and spotting afterward are common, as are irregular cramps that keep you awake without becoming labor. A sweep is a low-risk procedure that can shorten the wait for some women. It is not a procedure that changes how the birth ends.