My hospital has an affiliated hypnotist at their wellness and holistic center. I heard about him through a flier at the hospital and called.
He gave me one session, and sent me home with a cd which I listened to every other night. It definitely helped within weeks to make me feel more confident and less anxious about the prospect of my delivery. I benefited a lot from that calmer attitude.
I ended up having a rather challenging delivery that lasted for a very long time, so it isn't as though preparing through hypnosis totally spared me difficulty, but at some point, the nurse put on my cd, and I stopped shaking and I stopped throwing up and I stopped moaning. Just having that cd on really made the contractions bearable. It was very impressive. I think that, had I been in a home environment instead of in the hospital (where I was constantly interrupted for monitoring and such), I could have played it on constant loop for a while and gotten more respite out of it.
I would definitely recommend hypnosis to any woman preparing for childbirth. It certainly won't do any harm, and it might very well help relax you, which is such an incredible help.