A membrane sweep, also known as membrane stripping, is a common intervention offered late in pregnancy to encourage the start of labor before a formal induction becomes necessary. This elective procedure is performed by a healthcare provider during a routine internal examination. It requires full patient consent and aims to stimulate the body’s natural processes to begin labor, often around the estimated due date.
The Procedure and Purpose
The membrane sweep is performed during a pelvic exam. The healthcare provider inserts one or two gloved fingers through the cervix and uses a gentle, circular sweeping motion around the lower part of the uterus. This maneuver manually separates the amniotic sac from the uterine wall near the cervix without intentionally rupturing the sac.
The goal of this separation is to stimulate the release of prostaglandins. These hormones soften and thin the cervix, a process called ripening. This release helps prepare the cervix for labor and can potentially trigger uterine contractions.
Determining Eligibility for the Procedure
Eligibility for a membrane sweep is governed by gestational age and cervical readiness. Providers generally offer the procedure once the pregnancy is considered full-term, typically defined as 39 weeks of gestation or later. It is often offered around 40 weeks for first-time mothers.
For the procedure to be possible, the cervix must show signs of readiness, meaning it needs to be slightly dilated and effaced. If the cervix is completely closed or “unfavorable,” the provider cannot physically access the membranes to perform the sweep effectively. The decision to proceed is made in consultation with the healthcare provider, who weighs the potential benefit against the patient’s individual health circumstances.
The timing is often elective, intended to reduce the chance of the pregnancy progressing beyond 41 or 42 weeks, when post-term risks increase. The patient must give informed consent, understanding that the procedure may increase the likelihood of spontaneous labor but is not guaranteed to work. Multiple sweeps may be offered if the first attempt is unsuccessful.
What to Expect During and After the Sweep
During the membrane sweep, most people experience a brief period of discomfort, often described as feeling like an intense pelvic examination. The entire process takes only a few minutes, and patients can ask the provider to stop at any time.
Following the procedure, mild physical symptoms are common. These typically include mild cramping, similar to menstrual pain, and the onset of irregular contractions. Many patients also notice light vaginal bleeding or spotting mixed with mucus, known as a “bloody show.”
These symptoms indicate the body is responding to the stimulation and the release of prostaglandins. Discomfort can often be managed with simple measures, such as a warm bath or over-the-counter pain relief. Contact the healthcare provider if the bleeding becomes heavy (e.g., soaking through a pad in an hour) or if the pain is severe and unmanageable.
Serious Risks and Contraindications
While generally considered a safe, low-risk procedure in uncomplicated pregnancies, there are specific situations where a membrane sweep should not be performed. These safety limitations, known as contraindications, include conditions like placenta previa, where the placenta covers the cervix. The procedure is also avoided if there is an active vaginal infection, such as genital herpes, due to the risk of introducing infection to the uterus.
There is a small risk of the membranes accidentally rupturing during the sweep, causing the water to break before labor is established. If this occurs, the patient requires close monitoring to reduce the risk of infection. Other serious warning signs requiring immediate medical attention include heavy, bright red vaginal bleeding or a noticeable decrease in the baby’s movements.