Sterile water injections to help with back pain in labour

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What is this information about?

This information is about having sterile water injections into your lower back to help with back pain during your labour. It tells you about the advantages and the disadvantages of having these injections.

Why have I been given this information?

You have been offered sterile water injections, as they may help you during your labour.

If you experience severe back pain during labour, sterile water injections may help to reduce this back pain by up to 50 to 60%. This pain relief is often immediate, but usually starts within 10 minutes and lasts for 2 to 3 hours.

Reading this information can help you make a choice about whether you would like them or not.

How will I be given the injections?

Two midwives will each give you two small injections of sterile water. These go into your lower back, just under the skin. This is four injections altogether. If you are at a homebirth with one midwife, they can give you all four of the injections.

These injections can be painful for about 20 to 40 seconds. Because of this, they are usually given during a contraction. You can use gas and air as well if you want to.

How do these injections work?

No pain relief medication is given with these injections: it is just water! The injections work by causing a localised reaction to the water that stimulates the body’s natural endorphins (pain relieving hormones) which may help relieve the back pain. 

What are the advantages of having these injections?

• The effects of these injections are often immediate but usually you will feel the benefits within 10 minutes.
• They provide significant pain relief.
• They have no effect on your level of consciousness.
• There are no side effects on you or your baby.
• There is no chance of an allergic reaction or drug interactions (medicines affecting each other). 
• The significant relief often relaxes you enough to support labour progression.
• The relief from back pain can help you rest and recover between contractions.
• The injections can be repeated after 30 minutes, as often as you want.
• You can have them in combination with gas and air, using the pool, or morphine. You can have them at home, in a midwifery-led unit or on delivery suite.
• Having sterile water injections does not stop you from having any other pain relief, including epidurals, if you decide after having the injections you would like to have them.

What are the disadvantages of having these injections?

• When they are given, the injections are painful. This lasts for about 20 to 40 seconds. But the relief from back pain is often instant. This should help you to concentrate on the contractions rather than the intense back pain.
• For a small number of women, it does not provide enough pain relief (5 to15 women in 100). This is the same as any method of pain relief.
• These injections are specifically for back pain rather than contraction pain. However, the back pain can be constant, and you may find it difficult to cope with. Easing the back pain can help you feel more comfortable and make it easier to cope with contractions. It allows you to rest and recover between contractions.
• You will need to be in a position so that your midwives can reach your lower back (for example, sitting up without support, or on all fours). You will need to be able to stay still too. Holding onto your birthing partner or a pillow can help with this.

Who can I speak to for more information and advice?

For more information, speak with your midwife.