Sterile water injections for back pain relief during labour

Many women experience back pain during labour, particularly if their baby is in a posterior (back-to-back) position. Unlike contraction pain, which comes and goes, back pain can be continuous and uncomfortable throughout labour.

There are several ways to help ease back pain during labour, including massage, changing positions, using a TENS machine, or spending time in a bath, shower or birthing pool. Sterile water injections are another option and can help reduce severe lower back pain.

What are sterile water injections?

Sterile water injections are a drug-free option for relieving intense lower back pain during labour. They involve injecting small amounts of sterile water just under the skin in four areas of the lower back.

How do sterile water injections work?

The injections cause a brief, sharp, stinging sensation for around 30 seconds. They can provide significant relief from lower back pain within a few minutes. Pain relief may last for up to three hours.

Sterile water injections are thought to work by blocking pain signals travelling to the brain. They may also encourage the body to release endorphins, which are natural pain-relieving hormones.

Benefits of sterile water injections

Sterile water injections can offer several benefits during labour:

• Drug-free pain relief with no known impact on your baby
• No known side effects for you or your baby
• Fast-acting, with relief often beginning within minutes
• Can be repeated if needed
• Allows you to remain mobile, upright and active during labour
• Can be used alongside other pain relief methods and coping techniques

Are there any risks?

Sterile water injections are considered a very safe option for relieving lower back pain during labour. There are no known side effects for you or your baby.

Sterile water injections can be used before an epidural is given. If you decide later in labour that you would like an epidural, you can still have one after receiving sterile water injections. However, sterile water injections cannot be given once an epidural is already in place.

What happens when sterile water injections are given?

• Your midwife will give 4 small injections into specific points on your lower back during a contraction
• You will feel a sting or burning sensation for around 30 seconds, but this is normal
• Pain relief starts within minutes, and may last up to 3 hours
• It is important not to rub or touch the injection sites afterwards, as this may reduce their effectiveness

Is this option right for me?

Sterile water injections may be a good choice if you:

• Are experiencing intense lower back pain during labour
• Prefer to stay upright and active during labour
• Prefer to avoid stronger pain-relieving medicines or an epidural

Find out more

National guidance supports the use of sterile water injections as a pain relief option for women experiencing back pain during labour. If you would like to know more, speak to your midwife, who can discuss whether this option is suitable for you.

For more information, please refer to the National Institute for Health and Care Excellence (NICE) guidance Intrapartum Care (NG235) and the associated Intrapartum Care: Evidence Review C – Sterile Water Injections.

Entonox (Gas and Air)

A mixture of oxygen and nitrous oxide inhaled during contractions.

Benefits:

• Quick acting
• Easy to use
• Woman remains mobile
• Can be used at any stage of labour

Possible side effects:

• Dizziness
• Nausea
• Tingling sensations

Opioid injections

Examples include diamorphine, morphine, and pethidine.

Benefits:

• Can promote relaxation
• May help women cope with contractions
• Does not require specialist anaesthetic staff

Possible side effects:

• Drowsiness
• Nausea and vomiting
• May temporarily affect the baby’s alertness after birth

Remifentanil PCA

Remifentanil is administered through a patient-controlled pump, allowing women to self-administer small doses as required.

Benefits:

• Rapid onset and short duration
• More effective than intramuscular opioids
• Women remain in control

Considerations:

• Requires continuous monitoring
• May cause drowsiness and slower breathing

Epidural

An epidural is administered by an anaesthetist through a catheter inserted into the lower back.

Benefits:

• Most effective form of labour pain relief
• Can be topped up throughout labour
• Can be extended if operative birth is required

Possible side effects and risks:

• Reduced mobility
• Additional monitoring required
• May increase the likelihood of an assisted vaginal birth
• Difficulty passing urine, often requiring a urinary catheter
• Headache is an uncommon complication
• Serious complications are very rare

Limitations:

• Requires anaesthetic staff and can take time to establish
• Does not work immediately; full effect may take 20-30 minutes

Find out more

Information on pain relief choices during labour
Pain relief options in labour and birth (Tommy’s)