childbirth is a tough thing. watching your wife struggle through it? nothing harder to watch, especially since there's really nothing you can do to help. you're just there to comfort and help her keep focused.
my wife was 39 when our daughter was born, and it was a difficult delivery. i'm sitting at her feet and all i can think about is the ten thousand stories i'd heard all my life about women who died during childbirth. i could hardly stand it. because our daughter didn't drop done far enough, the doc had to use a suction cup to help get her out. cup kept popping off. he said "this is the last attempt. if she doesn't come out this time, we're going to do a c-section." that would have probably been a whole lot easier to watch.
i didn't stick around to watch him do the episiotomy or to sew it up.