If you want to talk about natural law, then I will counter - by natural law, the kid is alive and has a right to life.
Without medical care lots of people would die from lots of different things.
If disease or injury had claimed the kid's life, the kid would be dead, but it didn't and he didn't.
If you starve or suffocate someone they will die, that's true. One assumes that is what you mean when you say "natural law." Might makes right stupidity.
Yes, providing medical care for his kid is an expense related to pregnancy.Keeping her on artificial life support is not related to pregnancy.
Also, as already explained to you, there is nothing artificial about any of this from the kid's perspective.