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Labour pain relief: sterile water injections

For women who experience bad back pain in labour, sterile water injections can help to ease it. Here we explain about this more unusual pain reliever...

What are sterile water injections?

Sterile water injections involve tiny amounts of sterile water being injected into the skin around your lower back (sacrum) to relieve pain in labour. It might sound like something that shouldn’t work but there is some evidence it can help. It’s usually used for women experiencing strong back pain in labour (Derry et al, 2012).

How do sterile water injections relieve pain?

The idea is that the stimulus of sterile water injections might ‘shut the gate’ and prevent back pain or labour pain signals from reaching the brain (Fouly et al, 2018).

Midwives can give sterile water injections so these injections could be ideal for use in midwife-led units or other settings with less medical support (Fouly et al, 2018).

Are sterile water injections any good for pain in labour?

Two to four injection points are used to inject 0.1ml to 0.5ml of water so it forms small blisters under the skin (Derry et al, 2012; Fouly et al, 2018). The injections are painful so are usually given at the height of a contraction. The pain from the injection lasts about 30 seconds but after that, these injections might reduce the pain of contractions for two to three hours (Derry et al, 2012).

Injections can be repeated (Martensson et al, 2017).

There hasn’t been enough evidence to support the widespread use of sterile water for pain relief (Derry et al, 2012). But a more recent study found that women reported a significant reduction in their back pain during labour (Fouly et al, 2018).

Are sterile water injections suitable for everyone?

In theory, they might not be suitable for women with a rash on their lower back (RCM, 2016).

What are women’s experiences of sterile water injections?

Some studies have found that women say sterile water injections are effective. These women also said they suffered few side effects, and they appreciated the break from the pain that allowed them to focus on their labour (Lee et al, 2017; RCM, 2016).

Are there any side effects?

Women can get a burning pain at the injection site but this wears off within a minute of the injection (Derry et al, 2012; Fouly et al, 2018). No other impacts on the mother or baby have been found.

Do sterile water injections have any impact on labour or breastfeeding?

Nobody knows for sure yet whether sterile water injections have any impact on whether women have assisted births or caesarean births. But some midwives have suggested that they might reduce the chance of a caesarean (RCM, 2016).

No studies into the impacts of sterile water injections on breastfeeding have been conducted to date.

Are there any long-term effects?

The long-term effects haven’t been studied.

What if I don’t like sterile water injections?

The most difficult part of sterile water injections is the immediate reaction to them. Once the injection is complete, you might decide not to repeat it.

Are sterile water injections widely used?

Sterile water injections are not widely available. Despite them being a cheap, easy to administer and potentially effective method of pain relief, not a lot of research has been done into them (Derry et al, 2012; RCM, 2016). This might change when more research has been done.

When would I have sterile water injections?

You can have a sterile water injection in latent (early) or active (established) labour (RCM, 2016).

How can my birth partner help?

Your birth partner can help you to stay in a good position, comfortable, hydrated and emotionally supported. You and your partner are encouraged not to rub the blisters so a back rub on that area might be out.

Can I use other pain relief with sterile water injections?

Possibly not TENS as it would be working on the same part of the body. Water might be used after a sterile water injection (RCM, 2016). If you want more pain relief, you could choose to have an epidural.

Would I need any extra procedures with sterile water injections?

No additional procedures are necessary.

This page was last reviewed in August 2019.

Further information

Our support line offers practical and emotional support with feeding your baby and general enquiries for parents, members and volunteers: 0300 330 0700.

We also offer antenatal courses which are a great way to find out more about pregnancy and life with a new baby.

Research from the Royal College of Obstetricians and Gynaecologists (RCOG) about the use of water as pain relief in labour.

Derry S, Straube S, Moore RA, Hancock H, Collins SL. (2012) Intracutaneous or subcutaneous sterile water injection compared with blinded controls for pain management in labour. Cochrane systematic review. (1):CD009107. Available at:… [Accessed 9th August 2019]
Fouly H, Herdan R,  Habib D,  Yeh C. (2018) Effectiveness of injecting lower dose subcutaneous water verses saline to relief labor back pain: Randomised controlled trial. European Journal of Midwifery. 2(3). Available at:… [Accessed 9th August 2019]

Lee N, Kildea S, Stapleton H. (2017) “No pain, no gain”: the experience of women using sterile water injections. Women and Birth. 30(2):153-158. Available at: [Accessed 9th August 2019]

Martensson LB et al (2017) Sterile water injections for childbirth pain: an evidence based guide to practice. Women and Birth. 31(5):380-385. Available at: [Accessed 9th August 2019]

RCM (2016) Introducing sterile water injections as an alternative for pain relief. Available at: [Accessed 9th August 2019]

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Labour pain relief: sterile water injections

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