I used it with my first child 4 years ago. I also got fentanol (not sure how it's spelled) but I found it did absolutely nothing by the time they actually gave it to me. Not sure if the gas did much either but I do remember that it made my mouth REALLY dry, so if they'll let you have water or ice chips make sure you have a steady supply.
Thanks for the reply u think that is what we are going to opt for also.
No experience. I do not plan on any medication but I have opted to use nitrous oxide if I end up needing anything my midwife told me it's enough for some girls to get through the labor but that it's still painful cause it doesn't really take away the pain.