Cervical Sweeps - Everything you need to know

In this blog post, we’re talking all about Cervical Sweeps, also known as membrane sweeps, or stretch and sweep. NICE (National Institute for Health and Care Excellence) recommends that pregnant people should be informed that most of them will go into labour spontaneously by 42 weeks. NICE goes on to advise that at your 39 week appointment, your midwife should offer information about the risks of pregnancies that go on past 42 weeks, and discuss your options. One of these options is a sweep.

So what is a sweep?

A sweep is a procedure carried out by a midwife or doctor. As part of a vaginal examination, they will offer to sweep their finger around the opening and inside of the cervix (the lowest part of the uterus) to separate the amniotic sac from the uterine wall, which can release hormones to trigger labour. The aim is to stimulate the uterus to begin to labour earlier than it might have done without the intervention.  

But does it work?

Sweeps have become controversial in recent years, with reports of them being done routinely and without good, informed consent.  The Cochrane Library reviewed the literature on sweeps this year - and reported that slightly more women who had sweeps went on to go into spontaneous labour that those who did not (roughly 6 out of 10 without a sweep laboured spontaneously, and just over 7 out of 10 who had sweeps).  The study then looked at whether women who have sweeps are less likely to have a formal induction.  This is trickier to look at because there will be women who had elective caesarean sections, or who were advised to have an induction of labour for reasons other than going past 42 weeks of pregnancy - for example pre-eclampsia or prolonged rupture of membranes.  Bearing that in mind, the study found that without a sweep  313 women in 100 had an induction of labour.  With a sweep that number dropped to 228 in 1000.

NICE suggests that discomfort and a small amount of bleeding can be expected as side effects of a sweep. Some people will experience period-like cramping which can make them feel really uncomfortable, and perhaps interfere with sleep in the last few days of pregnancy.  

The overall report from Cochrane is that most people find the intervention of a sweep fairly tolerable, but of course like with everything the spectrum of experience is really broad.