This is a problem with some of the drugs they use during C-sections, too. When my son was born by surprise Caesarean, I think that was one of the things my wife and I were most worried about - that she would have no memory whatsoever of our son's first few hours of life.
FWIW that happens even when no surgery takes place. The women have just gone through a pretty traumatic effort. It's funny how terribly my wife recalls the first hour after she gave birth.
