If your reasons for creating life were selfish – and mine certainly were – then you need to acknowledge that every day. The fiction that you somehow did your child a favor for which they owe you is vicious and cruel.
I really enjoy it when analytical people talk about things that are more often glazed with sentiment ("Does my son have human rights. If so are they different than mine.") and it's a provocative question. You occasionally see people up the question of whether procreation is good on the basis of its environmental or demographic externalities, and such inquiries may be of growing interest. The United Nations has tipped October 31st as "7 Billion Day", which is a good Halloween scare if you take a Malthusian view of things or if you're troubled by Derek Parfit's "repugnant conclusion". But as the quoted bit suggests, Karl is looking at this with regard to the new people themselves: on what basis may we impose life on other people? It may be unanswerable, if the ability to be imposed upon is contingent on existing in the first place, and I would suspect that few parents are inclined to interrogate themselves this way. Actually, is it fair to argue that pregnant women have a normative responsibility to avoid potentially troubling data points or arguments on the basis that anxiety affects fetal development? If I'm ever pregnant that's how I plan to defend myself while eating sushi and skydiving.