Coping with pain in labour

Using gas and air (entonox) in labour

4 min read

Gas and air is a flexible pain relief option that you can use to manage contractions throughout your labour and in any birth setting. Find out why it’s the most popular form of pain relief – and if it could be right for you.

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What is gas and air?

Entonox, also known as gas and air or laughing gas, is an odourless mixture of nitrous oxide and oxygen. It works by temporarily reducing the pain you’re experiencing without blocking it altogether, although it’s still not clear exactly how it achieves that.

Gas and air is the most popular type of pain relief in labour – three quarters of women use it at some stage, according to a 2018 survey by the Care Quality Commission (CQC).

Where can I use gas and air when giving birth?

Gas and air is one of the most flexible types of labour pain relief available. You can use it:

If you’re having a home birth, your midwife will bring a gas and air canister to you, either in advance of the birth or when you go into labour.

Gas and air is also widely available in both birth centres and labour wards, usually administered through a pipe in the wall of the delivery room.

Use our Birth Choice tool to check what pain relief options are available where you’re planning to give birth.

How do I use gas and air in labour?

Entonox is inhaled through a mouthpiece and mask when you’re having a contraction.

It takes 15-20 seconds for the pain-relieving effect to start after you inhale, so it works best if you begin to breathe the gas in as soon as you feel a contraction starting, before the pain is too severe.

While gas and air can be used safely at any stage of labour, it’s usually best to wait to start using it until you’re in established labour.

You may also find that you need to stop using gas and air while you’re in the second stage of labour, when you need to push, as the effects of the entonox can make it more difficult to focus on pushing through the contractions.

What are the pros and cons of gas and air?

Here are some of the reasons why so many women choose to use gas and air:

  • You’re in control of how you use it: you can take it as often and for how long as you like and hold the mouthpiece yourself.
  • It’s safe for you and your baby: you don’t need any extra monitoring while you’re using gas and air and no side effects have been reported in babies of mothers who use gas and air.
  • It can be used alongside other pain relief methods: if you’re using natural pain relief methods, there’s nothing to stop you using gas and air as well. Many women also find it helpful to use gas and air when having an epidural administered.
  • The effects stop quickly if you stop taking it: if you don’t like the feeling of using gas and air or find that it doesn’t help you manage the pain, you can stop taking it immediately and the effects don’t last.

There are no lasting side effects associated with using gas and air, but some women find that it causes them short-term discomforts. Here are some disadvantages you may experience:

  • You may become disoriented, sleepy or confused: this is a common effect of entonox, especially if you inhale too much of it.
  • Feeling nauseous: some women find that entonox makes them feel queasy or even vomit and they can’t continue to use it for that reason.
  • Dry lips, mouth and throat: a lot of women find that the gas and air makes them very dry in the mouth. You can try to counter this by packing lip balm in your hospital bag and taking frequent sips of water during labour.
  • The pain relief effect is mild: while some women find it a helpful method of coping with pain on its own, many others do not find it effective enough and go on to use other methods.

More from Which?


These are the sources of information used in this article:

Care Quality Commission, Maternity Services Survey 2018 (2018)

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