Mrebo said:

By way of analogy, imagine a great uncle is in the hospital and declared brain dead. The family gathers by the bed to say goodbye. It is acceptable to pull the plug in such a situation because he is basically considered dead. But imagine if suddenly an eyelid fluttered or a finger moved, should we rush to pull the plug before he potentially and miraculously obtains consciousness? No. We are only pulling the plug because of a near certainty that won't happen.

if the uncle is truly brain dead, there is no way his eyelids will flutter. brain dead is dead.

one thing to remember about this analogy, is that the uncle, when he was healthy may have written a paper with instructions about what he wants done should he end up in this situation. The fetus can give no instructions.

edit: I failed to read Mrebo's link before making this post. A remarkable story. I have to say I am confused. If it is not unusual for a patient to have no detectable brain activity for several hours, why were the docs so sure was was gone that they sent her for organ harvesting? I still believe what I said about "brain dead is dead" to be true. I would argue in this case that even though there was no detectable brain activity for several hours, it doesn't mean she was actually brain dead. I would also argue there is a difference between no detectable brain activity, and no brain activity whatsoever. I have wonder what this woman's life will be like now. I would have to believe having no detectable brain activity for as long as she did, would have to cause some brain damage.