A membrane sweep is a method used to try and start labour artificially.
You may also know it as a stretch and sweep or stripping the membranes.
It’s commonly suggested as a means to start labour before trying medical induction methods.
A membrane sweep doesn’t involve any medication.
The idea behind a membrane sweep is to stimulate the production of prostaglandin, which is a hormone that prepares your cervix for labour.
Your care provider inserts a finger through your cervix and firmly moves their finger around in a circular motion, separating the membranes of the amniotic sac from your cervix.
A membrane sweep can seem like a better alternative to being medically induced. However it’s important to know it is still an intervention and you should be informed about your options to make the best choice for you and your baby.
6 Facts You Need To Know About A Membrane Sweep
Here are 6 facts to know about membrane sweeps:
#1: No Induction Method is Natural
One of the upsides to membrane sweeps is it doesn’t involve any medication. You may even hear it being referred to as a natural induction method.
Unfortunately that simply isn’t true. Any procedure that attempts to kickstart labour before it begins on its own is doing so by artificial means.
We know a little about the complex process of labour initiation and science has shown it involves a baby’s readiness for the outside world. You can read more about this in What Causes Labour To Start?.
However induction can be a life saving intervention, when continuing on with pregnancy puts mothers and babies at risk. Having the option of trying for a non medical induction method may put you at ease with having to be induced.
#2: It May Lead To Further Interventions
It can be tempting to try a membrane sweep when you are 38 weeks pregnant because your care provider is already talking induction at 40 week. You might feel completely over being pregnant, or worried your partner might not make it to the hospital in time.
But if a membrane sweep doesn’t bring on labour and your care provider doesn’t support waiting for labour to begin spontaneously, you are more likely to have a medical induction.
If your body and baby weren’t ready for labour to begin, you may end up with more interventions, such as forceps or vacuum assisted birth, or even a c-section.
Your baby may also experience problems due to being born early, especially breathing problems.
If an induction is necessary for medical reasons, a membrane sweep can seem like a gentler option than medical methods of induction. If you are in this situation, your care provider can assess your cervix and determine how likely a membrane sweep will help things along. You can also be better prepared for the possibility of needing more medical methods and have a plan for how to make those decisions.
#3: It Can Be Painful
If a membrane sweep is recommended for your situation, it can help to know what to expect.
During pregnancy, your cervix is closed and angled slightly back toward your tailbone (called posterior). When your body begins to prepare for labour, the cervix will soften and possibly even open slightly (around 1-2 finger widths). The position of the cervix can change and shift more forward.
However when these things happen differ between women and even pregnancies. Some women can have these changes happen in the weeks leading up to labour, others won’t until labour is noticeably beginning.
A membrane sweep is more easily performed if your cervix is what is called ‘favourable’. The cervix is soft, has shifted forward somewhat and is slightly open.
If the cervix is still posterior, it can be difficult for your care provider to reach, which can make the sweep uncomfortable or even painful.
If the cervix is closed but soft, your care provider can stretch or massage the cervix to stimulate it to begin to dilate. Stretching the cervix can feel very uncomfortable, and some women describe a sharp, shooting sort of pain.
After the membrane sweep, you may experience cramping and spotting or bleeding.
#4: You Have The Right To Decide
In a perfect world, no woman would ever have a medical procedure performed without her consent during pregnancy or birth.
Membrane sweeps are considered safe and effective in reducing pregnancy length, and this can lead to some care providers to do them routinely in the last weeks of pregnancy.
While this may be an option for women who are facing medical induction, it is still a procedure which needs your informed consent before it is performed.
You should be informed of this policy and your care provider needs to discuss with you the risks and benefits of membrane sweeping so you can make an informed choice whether to have the sweep or not.
Unfortunately, many women experience membranes sweeps during pre-natal appointments, and are not aware the procedure will be done until after it has occurred. This can be a very distressing and upsetting event.
#5: Safe And Effective
There is research showing membrane sweeps to be a safe and effective means of reducing pregnancy length and medical induction rates. Some of the studies show:
- A membrane sweep at 41 weeks can reduce the chance of going past 42 weeks and being induced
- On average a membrane sweep procedure shortens gestation by four days from when you would have gone into labour
- A membrane sweep can reduce the use of synthetic oxytocin and increase vaginal birth rates
Studies on outcomes for membrane sweeps differ, but this independent Cochrane review of 22 trials showed eight women would need to have their membranes swept to avoid one medical induction. The authors concluded membrane sweeping didn’t produce clinically important benefit.
#6: Membrane Rupture
There is an increased risk, although small, of your membranes rupturing prematurely after a membrane sweep. This means the amniotic sac surrounding your baby breaks and fluid will begin to leak out.
There is an increased risk of infection if this happens and labour doesn’t begin within a certain timeframe. Your care provider may want to move to more medical methods of induction and it is wise to be prepared for this possibility.
If induction is necessary for medical reasons, a membrane sweep is not usually performed on its own – other methods are usually used.
However, a sweep may be undertaken if your cervix is very favourable, in the hope of avoiding further interventions.
The choice to have a membrane sweep should be made with full consideration of the risks and benefits for your personal situation, regardless of your care provider’s preference.