A membrane sweep is a common intervention offered in late pregnancy to encourage labor. It aims to promote labor without immediate medical induction, typically considered when a pregnancy reaches full term.
Understanding the Procedure
A membrane sweep, also known as a cervical sweep or stretch and sweep, involves a healthcare provider inserting one or two gloved fingers into the cervix. The provider then performs a circular sweeping motion to gently separate the amniotic sac from the lower part of the uterine wall. This physical separation is believed to stimulate the release of natural hormones called prostaglandins.
Prostaglandins play a role in ripening the cervix by softening, thinning, and helping it to dilate, processes that prepare the body for labor. The procedure is usually offered around 39 weeks of gestation. For a membrane sweep to be performed, the cervix must have already begun to dilate, typically at least 1 to 2 centimeters.
Influence on Labor Onset
Evidence suggests that a membrane sweep can increase the likelihood of spontaneous labor, though it does not guarantee it. The effect is often modest, but it may help some individuals go into labor sooner than they would without the intervention. Some studies indicate that labor may begin within 48 hours to one week after the procedure.
For example, a review found that membrane sweeping was associated with a 24% increased chance of delivering within 48 hours and a 46% increased chance within a week. Another study showed that women who had weekly membrane sweeps starting at 38 weeks had a 90% chance of spontaneous labor before 41 weeks, compared to 75% in those who did not. This procedure is considered a gentler method to encourage labor, distinct from a full medical induction which often involves medications. It can potentially reduce the need for more formal induction methods.
Experience and Considerations
During a membrane sweep, it is common to experience brief discomfort, pressure, or a sensation similar to a rough pelvic exam. This discomfort is usually temporary and subsides shortly after the procedure. Following the sweep, individuals may notice some light vaginal bleeding or spotting.
It is also common to experience irregular contractions or cramping, which may feel like “practice” contractions. The loss of the mucus plug, sometimes referred to as a “show,” can also occur. While these symptoms are generally normal, it is important to contact a healthcare provider if there is heavy bleeding, severe pain, or if the membranes rupture (water breaks).
Deciding If It’s Right for You
The decision to undergo a membrane sweep involves considering gestational age and cervical readiness. A healthcare provider will also review an individual’s medical history.
There are situations where a membrane sweep may not be recommended, such as in cases of placenta previa or certain active infections like genital herpes. It is important to have a discussion with your healthcare provider to weigh the potential benefits against personal comfort and preferences. A membrane sweep is an optional procedure and not medically necessary for every individual.