Some people can conceive a child, but can’t carry one - they just lose them anyway. I think things even out in the end. I believe that intention carries some weight.
When it comes to human life (in this case innocent human unborn babies), I don't see how intention carries any weight when it comes to deciding whether they should live or die-- especially if one is responsible for creating them so that one should be selected and the rest should die. Just because one might argue that it is a good to bring one baby into the world, it doesn't negate the evil that is done when several other innocent human lives are destroyed as part of the process.