How can child birth be compared accurately to something guys can understand?

I was talking at work with a co-worker and he said that he heard that giving child birth was equally as painful as losing a leg… I say that is a bit drastic but just wanted to see what the fluther community has to say. Also, being ‘kicked in the nuts’ isn’t an answer I am looking for as women can not experience that as men cannot experience child birth, so lets keep it to things that both men and women can experience.