Pain relief doesn’t necessarily mean taking drugs. Fear – of not knowing what’s happening or what to expect – can make pain feel worse than it actually is. Learning to relax can make a big difference, as can feeling in control. Midwives should support women in their choice of using entenox and answer their questions.

Nitrous oxide/entenox are the most common form of pain relief used routinely in both hospital birthing suites and for homebirth. It is basically 50% Nitrous Oxide (laughing gas) and 50% air (oxygen, nitrogen, carbon dioxide etc).

The benefits of gas and air are that although it does cross the placental barrier to the baby the effects are very short lived and therefore there are not known to be any serious side effects with its use for the baby. The patient holds the mask to her face and breathes the gases into the lungs where it very quickly enters the blood stream. Nitrous Oxide reaches the brain within 15 seconds.

Nitrous oxide doesn’t stop the pain entirely, but takes the ‘edge’ off the intensity of each contraction. If the mother is relax, she will progress. If she is tense, she will not progress. Entenox helps to relax the muscles, and once the muscles are relaxed, the cervix will open.

What are the disadvantages of gas and air?

• It is only a mild painkiller.
• It may make a person feel light-headed or sick, but it means it works well.
• It dries out the mouth if you use it for long periods, so water will help.
• Some hospitals have mobile entenox machines which means a person can mobilize easily and getting into a comfortable position.
• It may take a while to get the timing right so that it’s effective at the peak of your contractions.

Gas and air is perfectly safe for a labouring woman to use during labour. Although Nitrous Oxide can make the patient drowsy and does pass through the placenta, it is eliminated very quickly by both mother and baby. Research has not found any negative effects to the baby when Nitrous Oxide is used.