You can have attraction at first sight...so men, based upon their infatuation with looks can have love on first sight. Unfortunately...it can end up being hate on first sight after a few years.
You can have "love" on first sight, but that doesn't mean he or she is the person you should end up with.
I think you do have LOVE at first sight of the birth of your children. If you don't feel love at the first sight of your firstborn child, that would be strange...unless there is something very powerful that might override it.