I used the gas for Mackenzie as I was too far gone to go for the epidural. (I was 9cm by the time I got to the hospital). The gas worked well for me as it helped with my breathing and gave me something else to focus on, mind you when they took it off me they had to tear it out of my hands! After a lot of pushing they used forceps and boy do they kill and then I had an e/c so ended up with a spinal. At our antenatal class they went thru all the options with the side effects so you just need to be aware of each side effect and then choose accordingly.