The gas on offer to women in labour is a combination of oxygen and nitrous oxide. It is administered through a mask or mouthpiece, and usually comes out of the wall in most birthing rooms.
The concentration of Nitrous Oxide that a woman in labour receives varies between 30 to 70%. As you breath in the gas, nitrous oxide enters the blood stream through your lungs and is quickly distributed around the body. It also passes just as quickly across the placenta and into your baby. Nitrous Oxide can be eliminated quickly from both you and your baby, as it is not broken down by the liver like narcotics (such as Pethadine).
Nitrous Oxide can be given at any time during labour, but is most likely administered during transition. It works by depressing the brain’s normal function, which may result in changing your perception of pain. Some women find it sends them high, makes them nauseous or has little effect.
- May take the edge off the pain.
- Extra oxygen can be beneficial.
- Helpful during transition, in easing the pain and giving you something to focus on.
- Can be used in water if it’s portable or wall mountings are nearby.
- You can remain awake and in control of your pain relief.
- Doesn’t interfere with contractions.
- Only remains in the body a short time.
- Depresses the brain’s normal function.
- Can cause nausea and vomiting.
- May make you confused and/or drowsing.
- Does not relieve pain entirely.
- You may not like having a mask on or breathing through a mouthpiece.
- Crosses the placenta with unknown effects.
I was going to use the gas, but I couldn’t even put the mouth piece in my mouth without feeling claustrophobic. — Allison
I think the gas really works because at one stage I looked over and saw my husband having a go, I was so annoyed I forgot about the pain! — Becky
Soon after I arrived at the hospital in the middle of a contraction, the midwife asked me if I wanted gas. I said — No, I don’t want any drugs. I want a natural birth.
She said to me — We’ll see about that.
It was repeatedly offered to me. I finally tried it. I got the giggles really badly. She said — Oh yes I’ve heard of that happening. Sometimes it is set too high. — I refused it after that. It just made me feel disorientated and I couldn’t stay in my body and feel what was happening and be present with the birth. I couldn’t go with the power of the contractions, it just made me feel out of control. — Michelle