A membrane sweep is a procedure offered in late pregnancy to encourage labor to begin naturally. It involves a healthcare provider manually separating the membranes of the amniotic sac from the lower part of the uterus, stimulating the body’s natural processes that lead to labor.
Understanding the Procedure
A membrane sweep is performed during a vaginal examination in a healthcare provider’s office. The provider inserts a gloved finger through the cervix. If the cervix is sufficiently dilated, they will sweep their finger in a circular motion between the amniotic sac and the lower uterine wall. This physical separation is intended to release prostaglandins, which are hormone-like substances that help soften, thin, and dilate the cervix, preparing it for labor. The procedure is usually offered after 39 weeks of pregnancy, when the cervix has already begun to dilate.
How Effective is a Membrane Sweep?
Membrane sweeps can increase the likelihood of spontaneous labor. For example, one study found that 90% of women who had a membrane sweep delivered by 41 weeks, compared to 75% of those who did not. Another review suggests it can increase the likelihood of spontaneous labor by over 20%.
Despite these findings, a membrane sweep does not guarantee labor will start, and its effectiveness can vary. It is generally considered more effective if the cervix is already “favorable,” meaning it has started to soften, thin, or dilate. While it may reduce the need for formal medical induction methods, it is not as effective as interventions like Pitocin. If successful, labor typically begins within 48 hours of the procedure.
What to Expect and Potential Risks
During a membrane sweep, it is common to experience some discomfort, which may feel similar to a rough cervical check. After the procedure, light vaginal bleeding or spotting is a frequent occurrence. Many individuals also report cramping or irregular contractions, which can sometimes be mistaken for the onset of labor.
While generally considered safe for full-term, healthy pregnancies, there are some potential risks. A small chance exists that the amniotic sac, or “water,” could break during the sweep. Any vaginal examination carries a minor risk of infection. It is always advisable to discuss the potential benefits and risks with a healthcare provider.