What is a sweep and how does it bring on labour?

If you get past your due date and your baby hasn’t arrived yet, your midwife may offer you a sweep. But what is it and how does it work?

A membrane sweep, sometimes referred to as a cervical sweep, is a procedure which can encourage your body to go into labour. Unlike an induction, which must be carried out at a hospital, your midwife can carry out the sweep during a normal antenatal appointment.

The advantage of a sweep is that it is drug-free but there is no guarantee it will work. You will normally be offered a sweep at your antenatal appointments at 40 weeks and 41 weeks but it is completely your choice whether it is carried out or not.

What happens when you are given a membrane sweep?

Your midwife or doctor will carry out an internal examination and sweep their finger around your cervix in a circular motion. The idea of this is to separate the membranes of your baby’s amniotic sac from the cervix itself, which will trigger the release of prostaglandins. These hormones produced by the body encourage the cervix to begin softening and thinning to start off labour.

Having a sweep shouldn’t hurt but it can feel uncomfortable. Internal examinations can be a difficult experience for some women so make your midwife aware if this is something you are worried about. You may experience a small amount of bleeding afterwards, which is nothing to worry about. It is not normal to experience a lot of bleeding though so if this does happen, always contact your midwife or maternity unit.

How quickly does a sweep work?

A membrane sweep will not start labour immediately but if it has been successful, you will usually experience the early signs of labour within 48 hours. You can have more than one membrane sweep and some women find it very effective to have a second sweep 48 hours after the first if it wasn’t successful.

After you have had a sweep, stay active if you can as walking can often help encourage labour to start. 

What happens if a membrane sweep doesn’t work?

If your sweep is not successful at starting labour, you will be offered an induction. This will need to be carried out at the hospital maternity unit where you will be looked after by midwives with doctors on hand to care for you too if necessary.

When you are induced, a pessary or gel will be inserted into your vagina to soften the cervix and encourage labour to start. This may not happen right away but you will need to stay in hospital while you wait for it to take effect and you may be offered another pessary or gel.

Sometimes, you may need to have a hormone drip to get your labour going if the pessaries and gels are not effective.

‍