While this seems like a pertinent question, there can be only one answer, right?
It is our humble recommendation to all men out there that they never, ever, under any circumstances ever, no matter what's going on or the context of the conversation or how much it really did hurt that one time when steel-tipped boots were involved EVER say that childbirth and getting kicked in the groin could be compared in terms of pain.
There are many reasons why this is a bad idea, but the main one is that, as the video explains, there's not really a scale to measure it, so it's hard to have a decent comparison. Still, this video does its best to explain how one would go about considering it anyway.
While the video has been around a while, it popped back up on our radar today and we thought it was worth a share. Just remember, only one of the two acts (childbirth/getting kicked in the balls) can be reenacted in order to perform a scientific study on short notice, and it ain't childbirth.