Read an article from "The Journal of Medicine and Philosophy" entitled "Rejecting the Baby Doe Rules and Defending a 'Negative' Analysis of the Best Interests Standard" by Kopelman. There are basically two standards for determining when it is best to end life support for infants with serious medical problems and the argument is that the "new" one is much less forgiving when it comes to situations concerning quality of life and that the old one give a little more freedom to the parents as well as the doctors when it comes to considering the suffering and difficulty an infant may go through. It's obviously a complicated and emotional issue and not one that has an easy answer. On the one hand life is precious and you don't what to leave the door open for abuse. But neither do you want to tie the hands of those faced with a decision no one wants to make but would probably make if they were in the situation themselves.
The only certain thing is that issues like this make it clear that the thing we all need to do, as individuals and as institutions, is to try to clarify our values. Clarification of all beliefs is important too, but when it comes to what we think is important, it is vital that we spend time thinking about them and how to deal with them in different situations. Our values really matter in life and too often we are faced with a problem for which we don't want the wrong solution. We have to be prepared. So go out there, sit down, and take some time to think about what you value and why and how and when and whatever.