I was only lucky enough to be present at the birth of my last child. My daughter was born in the Military Hospital in Singapore, just in time for the Chinese New Year celebrations in 1969.
The nurses/midwives present seemed to think that as it was the first birth I had attended, that I would be upset at the sight of blood. But the only time I was concerned was when what looked like a pair of gardening pruning shears were produced, to cut a membrane or something to make the opening bigger to allow my daughter to emerge. I felt really sorry for my wife, but luckily she never saw it happen, or felt it happen. I had seen plenty of blood before so it never bothered me at all.
Mind you if it had been my blood, it would have been a different story.