OK, I feel like I've been spending the past few days roleplaying as a pro-lifer and I'm sick of doing that, but this needs to be addressed:
Alright, the answer is simple:
Mercy kill.
In the former case, the child is condemned to a life of misery because the mother won't likely be able to provide for the child...or worse, as Scarlet pointed out, the child might become a magnet of resentment and be neglected anyway.
In the latter case, genetic defects could very well condemn the child to a really really short AND miserable life anyway.
This is a horrible,
horrible argument. You can't decide for someone else that they're better off dead than alive. If you believe that the fetus is a person just like a grown human being, then saying that "mercy kill" is acceptable for the former is tantamount to saying it's acceptable for the latter. And you know where that takes us.
I actually have to recognize that the "tacit consent" argument makes some modicum of sense (and I'd even go as far as to say that it's not
intrinsically misogynistic, though it has obvious misogynistic implications), though I don't think many people sincerely hold this position. But it's still infinitely less awful than the one you're making here.