Gas & Air aka Entonox, is a popular choice for pain relief during labour. In most hospitals, gas and air, is plumbed into the wall giving the person in labour an unlimited supply. In a home birth setting it is provided in large cylinders which can be replaced and refilled as required. The gas & air is always attached to a large pipe, enabling the person using it to move around during their labour and change their position with ease. It can be used on its own, or in conjunction with other pain relieving options such as the birthing pool, TENS, pethidine and even with an epidural for any breakthrough discomfort.


What are the side effects?

It doesn’t cross the placenta to the baby so it doesn’t have any proven side effects for them. Side effects for you may include – feeling dizzy, nauseous, a change in the sound of your voice, hysteria (laughing), dry mouth and tingly fingers. All these side effects pass as soon as you stop using the gas and air and breathe fresh air (which is beneficial to do between contractions).

How to use it effectively
Gas & air is inhaled through a mouthpiece throughout the duration of a contraction with the aim of it reaching peak effectiveness at the peak of the contraction.

Here are some of the top tips I often share with anyone who is thinking of using it:

  • Breathe in as soon as you start to feel the sensation of a contraction begin. This means that by the time it kicks in (after 20 seconds), you will get the benefit of pain relief at the peak of your contraction.
  • Breathing should be slow, deep and steady – the breathing you can learn in Nurtured Pregnancy Classes is perfect for this. Timing is essential to enable the gas & air to be effective so the midwife may talk you through the first couple of contractions until you are confident in using it properly.
  • Remember to keep as relaxed as possible. It is natural to tense your hand and your jaw around the mouthpiece but that can cause tense muscles in the rest of your body; making contractions seem harder as your other muscles direct oxygen away from your uterus and potentially making your uterus work harder.
  • Remember the phrase “Relax your jaw to release your pelvis” to keep your body relaxed during contractions. Or even doing what the couple in the picture are doing and get your birth partner to hold the mouthpiece.


  • Try to avoid using it in between contractions otherwise you might find yourself too relaxed or find it less effective – stick with using it for the contractions only.⠀
  • Keep a bottle of water with a straw nearby as you may find your mouth can get very dry. And use your lip balm!
  • Remember positions and movement is still really important. The hands and knees image above is amazing to show how you can use movement during contractions to help everything work as efficiently as possible and to keep you relaxed.

You can use it in most birthing situations so know that it’s there for you to use – you never know you may not need it!⠀

Have you thought about using it for your birth or did you use during your birth?