I've witnessed 2 births. First one was a nightmare, our son was face to pubes (wrong way round) and had swallowed the amniotic fluid from the sack that surrounds the baby. It got touch and go for a while and a specialist was called for. He took one look at my missus and took a scalpel from front to back, got the ventouse (sp) and literally sucked our son out by the head. He was immediately taken from us, had tubes put down into his lungs to clear the fluid and was only brought back after a half-hour of panic. In the meantime Mrs. cT had to endure somewhere around 30 stitches to her nether regions, but forgot all the pain when we were eventually presented with the boy.
Our daughter on the other hand, slipped out in a couple of hours, but to be fair, it was a bit like the Mersey Tunnel down there after the first one.