Understanding Membrane Sweeps: What They Are and What to Expect
A membrane sweep, commonly known as a “sweep,” is a procedure often offered towards the end of pregnancy to encourage labour to start. It is considered a form of induction since its goal is to prompt the body to go into labour earlier than it might have naturally. However, unlike other induction methods, a sweep doesn’t require immediate hospitalization, allowing you to remain in your chosen birthing environment once labour begins.
The Process of a Sweep
During a sweep, a midwife or doctor performs a vaginal exam and inserts a finger into the cervix, if it is open.
They then try to separate the membranes surrounding the baby from the wall of the uterus. If the cervix isn’t open enough for this, they may attempt to sweep around the outside of the cervix.
This process is intended to irritate the cervix and uterus, stimulating the release of prostaglandins, which can help kick-start labor.
What Does the Evidence Say?
It’s challenging to measure the effectiveness of sweeps because labor typically happens at the end of pregnancy anyway. If labor starts shortly after a sweep, it’s impossible to know if it would have happened naturally. According to a Cochrane review that analyzed various studies, sweeps in first-time parents did “not seem to produce clinically important benefits” in reducing the need for further induction interventions.
However, many people still opt for a sweep as a first step to avoid more invasive induction methods. Sometimes, attempting a sweep can provide mental relief, giving you the sense that you’ve tried everything possible to encourage labor naturally.
Keep in Mind
The cervix can change rapidly. If a sweep shows that your cervix isn’t quite ready, don’t get disheartened—labor can still start at any moment. Keeping oxytocin levels high through relaxation and positive experiences can also support the process.
Potential Side Effects
While a sweep can be beneficial for some, it also comes with potential downsides:
- Discomfort and Early Labor Signs: Sweeps can induce sensations similar to early labor, which may lead to prolonged discomfort and exhaustion. This can sometimes result in a higher use of epidurals and further interventions.
- Bleeding and Cervical Discomfort: The procedure can cause bleeding and discomfort, potentially affecting oxytocin levels, even if the bleeding is harmless.
- Risk of Membrane Rupture: In some cases, a sweep can cause the membranes (waters) to break. This starts the clock on hospital policy for how long labor can proceed before further interventions like induction or cesarean are recommended. While the choice of how long to wait remains with you, this situation can lead to more decisions and may impact oxytocin levels.
Making an Informed Decision
Deciding whether to have a membrane sweep is a personal choice. Some find it a useful first step to try and avoid more invasive induction methods, while others prefer to let labor start naturally. If a sweep is recommended to you, it’s essential to weigh the pros and cons, consider how you feel about the potential side effects, and remember that your body’s readiness for labor can change quickly.
Resources for Further Reading
- What is a Stretch and Sweep? by Sara Wickham
- Evidence Based Birth Podcast – Episode 6: Pros and Cons of Membrane Sweeping
A sweep can be one of the many tools available to encourage labor, but it’s important to understand what it entails and how it might affect you. As with all birth-related decisions, being informed and trusting your instincts will help guide you toward the choice that’s right for you.
