A lot of it is down to luck. My dd had a very difficult first birth, despite a fantastic hospital and very good care, loads of stitches, very uncomfortable for ages. All her idealistic notions of a completely natural birth flew out of the window, through no fault of her own.
2nd time, only just made it to the same hospital, 3 hours start to finish, not one stitch.
I had my two late 70s and early 80s, and yes, there were enemas and whatnot, but I was very grateful for excellent care both times with births that were not easy. I remember being so thankful for a modern hospital and help available, as opposed to a granny of mine who was in first time labour for 3 days at home - such a traumatic experience that she never had another baby.