Christians: What happens to babies that die right after they are born?

if God judges you based on your actions and your faith in him during your life, what happens to babies that die instantly after birth? They have no time to have faith in God, or time to sin in any way, so what happens to them? They go to Heaven I guess.. but isn't that unfair to everyone else? They get to go to Heaven, although if they had lived and been atheists, they would have gone to Hell.. If God was so perfect questions like these should not exist.