A stretch and sweep, also known as a membrane sweep, is a common, low-intervention technique offered late in pregnancy to encourage the natural onset of labor. It attempts to stimulate the body’s processes without medication-based induction. This optional procedure serves as a potential intermediate step before considering more formal medical induction processes. Expectant parents should discuss the risks and benefits with their healthcare provider.
The Purpose and Timing of the Procedure
The primary goal of a membrane sweep is to increase the likelihood of spontaneous labor, reducing the chance of requiring a medical induction. Healthcare providers often suggest this option to women nearing or past their estimated due date to avoid complications associated with prolonged pregnancy. The procedure is typically first offered around 39 to 40 weeks gestation, though timing varies based on clinical guidelines.
For the sweep to be performed, the cervix must be considered “favorable.” This means the cervix needs to be partially dilated and softened enough to allow the clinician’s finger to pass through the opening. If the cervix is firm and completely closed, the procedure is often not possible or may be less effective. The stretch and sweep is a quick, outpatient procedure usually performed during a routine prenatal appointment.
How the Stretch and Sweep is Performed
The procedure is carried out by a midwife or doctor during an internal vaginal examination, similar to a cervical check. The clinician inserts one or two gloved fingers into the vagina to locate the cervix. If the cervix is sufficiently open, the clinician gently inserts a finger just inside the cervical opening.
The physical action involves using a circular, sweeping motion to separate the amniotic sac membranes from the wall of the lower segment of the uterus. This mechanical stimulation triggers the release of local hormones called prostaglandins. These naturally occurring compounds help to soften, thin, and dilate the cervix, which are necessary steps for labor to begin.
Expected Sensations and Post-Procedure Experience
During the stretch and sweep, many women report discomfort, often describing it as sharp pressure or intense cramping, though the procedure is very brief. The physical action of separating the membranes causes this temporary, intense feeling. The level of sensation varies, and the clinician should stop if the discomfort becomes intolerable.
Following the procedure, it is common to experience physical changes as the body reacts to the stimulation. Most women notice light vaginal bleeding or spotting, typically dark brown or pinkish, which may be mixed with mucus, known as a “bloody show.” Mild cramping is also common and can sometimes feel like irregular contractions that do not develop into established labor. Heavy, bright red bleeding or a sudden gush of fluid is not a typical response and requires immediate contact with a healthcare provider.
Success Rates and Available Alternatives
The effectiveness of a membrane sweep is variable, but studies suggest it increases the chance of labor starting naturally compared to simply waiting. For many women, the procedure can increase the probability of going into labor within 48 to 72 hours. Research indicates that a sweep can increase the chance of delivery within a week by about 24% compared to expectant management.
Since success is not guaranteed and the effect is often cumulative, a healthcare provider may offer multiple sweeps spaced a few days apart if the first attempt does not result in labor. If the stretch and sweep is unsuccessful or not desired, the next steps involve more formal medical interventions. These alternatives include pharmacological methods, such as synthetic prostaglandins (vaginal gel or pessary) to ripen the cervix, or mechanical methods, such as inserting a balloon catheter to encourage dilation.