Re: Pregnancy, Childbirth & the ABCs …
If you’re going for this option then do keep plenty of fluids in handy…it makes you really thirsty. I think “laughing gas” is another name for “gas and air”. It makes you feel like you’re flying in the air and tickles your body. I had it too much with my 2nd baby and it knocked me out completely for few minutes. 
But yeah I found it very helpful during the contractions. Once you’re fully dilated and ready to push you won’t be allowed to have it as it can slow down/stop the process of birth and hence can be dangerous for the baby.