When it comes to those issues, nobody does. That's what the courts are trying to define as we speak. (like they're the best to make those decisions!)
When I was a medical student at Jefferson Hospital in Philly, our NICU would try to save premies down to 24 weeks. At that time ('92) 24 wks was considered the age of viability, with a 50% survival rate. Even with those "odds" many decided for comfort measures, and let the baby return to peace, given the high rate of complications and so forth. NOW, we're down to 20 weeks, and the REAL ethical issue is becoming the "artificial womb". As technology advances, we may move beyond the test-tube baby having to be implanted into a woman AT ALL! I mention that to demonstrate the HUGE ethical issues we'll be facing soon. Surrogate mothers will be obsolete. Gay male couples will be able to have a baby "made" for them if they choose! If a mom is caught three times with drugs on board, could a court order her fetus removed and placed in the "protective custody" of an artificial womb for it's own good?
These may seem obscure or extreme, but they are questions that we as humans, and supposedly "free" society, will be facing. The questions I originally posted here are going on right now. There was one doc at the conference who gives ALL his patients a letter encouraging them to share all their medical conditions with their children and relatives, so in case one of them turns out to be hereditary, he can say he "warned" them! Crazy, huh?
Thanks for your reply, I'm fascinated by what others think about this stuff. I don't think there's any right or wrong answers, and if anyone else does, I find that interesting too!