If you're overdue or there's any sort of risk to you or your baby, then your midwife may recommend booking in for a membrane sweep to help kick-start labour. Our expert midwife explains the pros and cons of a cervical sweep

What's a membrane sweep?

If you reach your due date and there’s no sign of your baby making an entrance into the world any time soon, then your midwife may recommend you have a membrane sweep (also called a cervical sweep) ¹ . According to the NHS , a membrane sweep will usually offered before a hormonal induction to try and kickstart labour naturally.

‘A sweep may be offered to you by your midwife or obstetrician when you’re around 40 or 41 weeks pregnant , depending on whether this is a first or subsequent baby for you,' explains Netmums’ official midwife, Leah Hazard.

'It’s a drug-free procedure that may help initiate the very early stages of labour if your cervix is already undergoing some pre-labour changes.

'It may be slightly uncomfortable but should never be painful and, if it works, it can help some women avoid the more complicated intervention of induction .'

The pros and cons of having a membrane sweep

Pros:

• It’s a natural method of stimulating labour (even if it doesn't exactly feel ‘natural’!) ²
• It may mean you avoid further intervention ² .
• You can have it performed at home, in an antenatal clinic or in hospital ² .
• It's a quick procedure that can be done in just a few minutes.
• The effects are quick too! Most women will go into labour within 48 hours after a membrane sweep ³.

Cons:

• It can be uncomfortable ² .
• You may experience some light bleeding or cramping after the procedure ¹ .
• Although it works in lots of cases, there is no guarantee that labour will start after a membrane sweep.
• A membrane sweep may not be suitable if you have a high-risk pregnancy or underlying health conditions – for example, if you are likely to need a caesarean.
• There's no evidence that having a membrane sweep can cause your waters to break ⁴ .

What happens during a sweep?

‘A sweep is performed as part of a vaginal or ‘internal’ examination,’ says Leah.

‘The doctor or midwife inserts one or two fingers into the vagina and, if the cervix is open at least a fingertip’s width, then one finger is inserted through the cervix and is swept around the base of the amniotic sac or "bag of waters".

'It’s thought that by separating the sac from the cervix, prostaglandins are released which can initiate early tightenings or contractions.

'A membrane sweep should take less than a minute, and you can tell your midwife or doctor to stop at any point if it’s too uncomfortable.’

You may experience some light spotting and cramping after a sweep; these are usually nothing to worry about ⁴ . However, you should always contact your local maternity triage unit if you’re worried, particularly if there's a lot of blood, or you're in severe pain ⁴ .

There is varying evidence about the effectiveness of membrane sweeps, but in general, labour tends to start a few days earlier in women who've had a sweep , compared to those who haven't ⁴ .

If a sweep doesn't kickstart labour for you, you might be offered a second and sometimes even more sweeps ⁴ .

If labour still hasn’t begun and you’re well past your due date or there are other concerns about you or your baby, your midwife or doctor might suggest setting a date for you to be induced (have your labour started artificially with hormones) ¹ .

Will I need a membrane sweep?

‘You are likely be offered a sweep if you are overdue (40+ weeks pregnant), as it can help to get things going,’ says Leah.

You should not have a membrane sweep if:

• your waters have broken ⁴
there's a medical issue that means your baby needs to be born very quickly via medical induction ⁴
• you've had problems with vaginal bleeding in your pregnancy ⁴

If you're having twins or more , your doctor or midwife will probably recommend that you have a planned birth if you haven't gone into labour by 32-37 weeks (depending on whether your twins share a placenta and chorionic sac) ⁵ .

A step-by-step guide to having a membrane sweep

• At your appointment your midwife or doctor will explain the procedure and any risks or benefits. This is a good opportunity for you to ask any questions, and express any concerns you might have about the procedure. ‘It’s important to feel safe and well informed before any internal examination,’ says Leah.
• Once you’ve consented to the membrane sweep, you will be given some privacy to undress from the waist down and lie back comfortably on an examination table or bed.
• Your midwife or obstetrician will again confirm that she has your consent, and will then insert one or two lubricated fingers into your vagina and feel for your cervix ⁴ .
• If your cervix is still closed, the midwife will not force it open. She will withdraw her finger and let you know that she’s been unable to do the sweep.
• If your cervix is open enough, she’ll pass a finger through it and make gentle circular, sweeping movements just inside it to try to separate your amniotic sac from the cervix.
• The midwife will withdraw her finger and give you some privacy to get dressed before having a chat about her findings and any potential side effects to look out for over the coming hours.

Your midwife will discuss the next step. If the sweep hasn’t worked, then another sweep may be suggested after approximately 48 hours or at your next appointment. Alternatively, an induction date may be set, or other plans may be made to suit your preference ¹ .

You’ll go home and probably be advised to wear a sanitary pad (for discharge, minor blood loss or if it triggers your ‘show’) and to have a warm bath to help relieve any mild cramping (which is normal, and can even be a good sign that your uterus is beginning to have gentle contractions).

Try to get some rest – if it works, you could be meeting your baby any day now.

Does a membrane sweep hurt?

‘A sweep can feel a bit strange or uncomfortable, but it should never be painful,’ says midwife Leah.

‘Let your midwife or doctor know if you’re particularly nervous or you have any concerns beforehand. If the procedure becomes unbearable at any time, tell the person doing it and they should stop immediately.

'If you’re unable to tolerate a full sweep, that’s fine – it’s not an essential part of your pregnancy, just an optional way to stimulate early labour.’

For some, the thought of a sweep can be worse than the actual procedure, particularly as this may be the first time you’ve had an internal exam.

‘A membrane sweep is a good opportunity for you to discuss your feelings about internal exams, which are likely to be a part of your care in labour, and for you to talk about your preferences for induction if labour doesn’t start spontaneously’ says Leah.

‘Either way, it can be exciting to know that your pregnancy is drawing to a close and you’ll be meeting your baby very soon.’

The best things to do after a membrane sweep?

It’s safe to go about your normal day after a membrane sweep. You can have a bath or shower, eat and drink as normal, and even have sex if you like (as long as your waters haven't broken - if your waters break, contact your midwife) ¹ .

‘There’s no need to avoid any particular activity,’ says Leah, ‘and likewise, there’s no evidence that doing anything specific after a sweep will increase its effectiveness.’

You may have some light spotting (minimal pink, brown or dark red bleeding, sometimes mixed with mucusy discharge) , but contact your local maternity unit if the bleeding becomes much fresher or heavier at any time ⁴ .

Read our advice on which tips may help bring on labour – and which may do more harm than good.

Do I have to have a membrane sweep?

‘The simple answer is, no, you don’t. It’s entirely your choice,’ says midwife Leah.

‘As long as it’s safe for you and your baby, you can decline a sweep and either wait for labour to start naturally or opt to be booked in for an induction at a suitable time, if you prefer.

‘Either way, discuss your decision with your midwife, as she may be able to reassure you or address whatever’s worrying you about this final stage of your pregnancy.’

Do membrane sweeps work?

‘Unfortunately, they’re not a guaranteed way of starting labour, and will usually only work if your cervix is already showing some pre-labour changes (opening, thinning and softening),' says Leah.

'Some women need more than one sweep to get things going, while others may still need to be induced after two or three sweeps.'

The NHS suggests that, if the membrane sweep is successful, you will usually go into labour within 48 hours ² .

According to a recent meta-analysis (a study that combines the results of many other studies), women who have at least one membrane sweep between 38-42 weeks are about 20% more likely to go into labour without further medical help (such as a medical induction or c-section) ⁶ .

Netmums tell us about their membrane sweeps

'I was 40 weeks on Monday and had one ... I've never had a smear or anything so didn't know what to expect. But it honestly wasn't that bad, it wasn't painful but was a little uncomfortable!'

'I had a sweep and it was not painful at all. It worked and sent me into labour at 39 weeks.'

'I started early labour with one of my sweeps and started contracting, and then I had two more. It helps if you're not stuck in a hospital bed like I was, in early labour, so I advise you when you do have your sweep go for long walks during the day to kick start things.'

'It was very uncomfortable, and afterwards I did have pain inside for the rest of the day. Not unbearable, but there all the same. I had the sweep at midday, was in labour at midnight, had my daughter by 6am. So yes, it worked!'

Chat to other mums about their experience, or share yours in our chat thread below:

Related stories

The signs and stages of labour

CHAT: How effective is a membrane sweep?

20 things no one tells you about giving birth

Sources

• ¹ NHS. 2020. Inducing labour . [^]
• ² North Bristol NHS Trust. nd. Membrane sweep . [^]
• ³ Cleveland Clinic. 2021. Membrane sweep . [^]
• ⁴ Journal of Midwifery & Women's Health. 2018. Membrane sweeping . [^]
• ⁵ NHS. 2019. Antenatal care with twins . [^]
• ⁵ Avdiyovski et al. 2019. Membrane sweep . [^]