Membrane Sweeps: What Are They, Do They Work, and Do You Have to Have One?

If you’re pregnant, you’ll probably have heard about membrane sweeps (sometimes called a stretch and sweep, or simply just a sweep) - but if you have no clue what we’re talking about, you’re in the right place! This blog post is going to tell you everything you need to know about membrane sweeps, so that you can make the choices that feel right for you during your pregnancy.

What is a membrane sweep?

A membrane sweep is a form of induction according to the NICE guidelines. It’s a way of trying to stimulate your labour to start, but without using medications or requiring you to be admitted to hospital. It requires a vaginal examination and we’ll go into more detail about what the procedure actually entails further down in this article.

When is a membrane sweep offered and why?

In the UK membrane sweeps are offered from 39 weeks of pregnancy. This is because UK guidelines recommend that all women be offered a formal induction of labour from 41 weeks, so sweeps are offered to try and avoid the other methods of induction.

What does a membrane sweep involve?

Before we even get into the nitty gritty of what a sweep involves, the most important thing to say is that the midwife (or doctor) should first explain what a membrane sweep is, what the benefits and risks are and then gain your consent prior to doing a membrane sweep. If you don’t have this information about membrane sweeps, you can't make an informed decision and you shouldn’t have a sweep if you haven’t given your explicit consent. Find out more about what consent really means from Birthrights, the human rights in childbirth charity.

Now on to what actually happens during a membrane sweep.

1. You will be asked to remove your underwear and lie on a bed (this could be in a community midwifery clinic, a hospital, or at home if you’re planning a homebirth). You’ll ideally be in a ‘semi-recumbent’ position - or slightly propped up with pillows. You should be given a sheet to cover yourself, and you can ask for one if not.
2. You’ll be asked to bring your ankles together and your feet up towards your bottom and then to let your knees open wide. The midwife will have washed their hands and should check that you’re happy to go ahead, they’ll then apply a pair of gloves and some lubricating jelly (which will probably feel quite cold) to their fingers. Before they start the procedure, they should again ask if you’re happy to go ahead with the vaginal examination. All this should be said in plain english so you know what to expect. Once you’ve given your consent, they will gently part your labia and then insert two fingers slowly into your vagina. You might be encouraged to take some deep breaths to help relax your pelvic floor.
3. The midwife will then try to locate your cervix (neck of the womb) and check to see if it is open (dilated) at all. During pregnancy, your cervix is usually a long closed tube that is pointed towards your bottom (posterior) - particularly if it’s your first baby. If your cervix is very posterior (which is completely normal!), it can be helpful to either place a rolled up towel under your buttocks or for you to place your fists under your buttocks - the latter can be quite uncomfortable, so a towel might be the better option. If you’ve given birth before, your cervix may be a little bit open. If the midwife can’t locate your cervix or if it’s tightly shut, the membrane sweep can’t be done. In this scenario it’s up to you if you choose to try and have another sweep at a later date.
4. If the midwife can find your cervix and can feel that it is slightly open, they will be able to do the membrane sweep. In our humble opinion, at this point we believe your midwife should also check in to see how you’re coping with the examination before they start the sweep. If you’re happy, the midwife can start the sweep by moving their fingers around your cervix and possibly stretching it a little if they can. The actual sweep may be anywhere between 30 - 60 seconds - however if you find any part of the examination too uncomfortable or painful you can ask the midwife to stop.
5. Once the sweep is done, the midwife will remove her fingers gently and should inform you of the findings, which will include information about how open your cervix is, how long it is, how soft it is and perhaps where your baby’s head is in relation to your pelvis. They’ll offer you some towels to wipe away any jelly, mucus or blood and should give you privacy to get dressed.

Does a membrane sweep actually work?

A Cochrane review looking at membrane sweeping concluded that, ‘Membrane sweeping is probably effective in increasing the likelihood of achieving a spontaneous onset of labour. When compared to expectant management, it potentially reduces the risk of formal induction of labour.’ The authors did however note that the evidence to support this claim was of low-certainty and the results should be used with caution. What’s also interesting to point out is that the Cochrane review authors say membrane sweeps may achieve spontaneous labour, but we should not forget that membrane sweeps are still a form of induction of labour.

If you ask friends and family you’ll probably find a mixed bag of reviews on sweeps. Some women will tell you they went into labour within 24 hours of a sweep and that it didn’t feel like a big deal. Others might say they had to have multiple sweep attempts because their cervix wasn’t ready. And some might say that the sweep was incredibly painful and uncomfortable.

If you know you would accept a formal induction of labour at some point during your pregnancy, then having a sweep might feel like a good option to try and potentially avoid a long hospital stay and long induction process. If on the other hand you are someone who knows that you would be very unlikely to accept a formal induction of labour, then you might feel that having a membrane sweep is unnecessary if you’re comfortable to wait for your baby to come when they’re ready.

What are the risks or side effects?

The potential risks or side effects of having a sweep include:

• Pain or discomfort during the procedure.
• Bleeding from the cervix - it’s very vascular (which is a fancy way of saying it has an excellent blood supply) and so sometimes can bleed if it’s prodded and poked. This bleeding shouldn’t be very heavy or ongoing, but it is often bright red and that can be alarming. If you are concerned about it, you should contact your maternity triage.
• Rarely the waters can be accidentally broken during a sweep. This then potentially sets a timer on your labour as you will be advised to have an induction if you haven’t gone into labour by 24 hours following your waters being broken. It’s still your choice to accept that induction offer if it comes to it, but essentially your waters being accidentally broken can throw you a bit of a curveball.
• Sometimes having a sweep can stimulate irregular, painful contractions before your labour properly establishes. This can be very tiring as the pain and discomfort can prevent you from being able to rest in the last few days of pregnancy. Sara Wickham also highlights that these irregular contractions can cause some women to go into hospital thinking they’re in established labour when they’re not quite there yet, and simply being in hospital can expose women to interventions that may not be necessary.

What are the pros?

The main pro of a sweep is that if it does work and your contractions start and your labour establishes - you’ll have avoided having a formal induction of labour. Induction of labour carries its own risks and is more likely to lead to other interventions. So avoiding that can be seen as a plus, if you’re someone who would have considered having an induction of labour at some point anyway. We hold the view that if a sweep does appear to set labour off - your body was probably very ready anyway.

Do you have to have a membrane sweep?

No! You don’t have to do anything during your pregnancy. If you have care in the NHS sweeps will most likely be offered from 39 weeks (sometimes sooner depending on your individual circumstances), but just because its policy to offer a sweep does not mean it’s mandatory. You should never be pressured or coerced into having a sweep - not by friends, family or healthcare professionals. The decision to have a sweep or not should be entirely yours. The BRAINS decision making tool can be useful in this scenario to help you decide.

Questions to ask before agreeing to a sweep

• Do you feel the need to try and get your labour started? And if so, why?
• Are you feeling pressured into having an induction? Or do you have an induction booked that you are happy to have, but would like to see if you can avoid the formal methods of induction?
• If you decline a sweep now, would you consider one at a later date?
• If you decline a sweep now, would you like to be offered another one or would you prefer it not to be discussed again?
• If the sweep is unable to be done, would you consider trying again at a later date?
• Have you thought about what you would do if your waters did break, or if a sweep set of niggly, uncomfortable-but-not-established-labour contractions?

How Juno Midwives support informed choice around membrane sweeps

Sweeps are something we discuss with all our clients in the context of explaining what the NICE guidelines recommend. It’s entirely up to you if you choose to have a sweep or not! We’re happy to do them if you want one after having a discussion about the pros and cons, and we’re happy if you decide you don’t want any at all. We’ll never pressure you one way or the other as the decision is not ours to make. We can signpost you to extra resources and information about sweeps and induction of labour in general.

If you’re interested with working with us, book your free intro chat via the button below - we’d love to meet you!