you might not be conscious if you don't understand consciousness
birth is the cutoff since everyone considers a baby a baby after birth, since it's too big to continue living off of its mother, and because it would be too difficult to take on case-by-case of whether a baby has lived long enough to become conscious. life is irrelevant if it has never been conscious.
How do you know a baby isn't conscious? Consciousness isn't defined by memory. If it were, amnesiacs and those with severe dementia would be without consciousness.
We can only look at this from a medical perspective as well. We can't define life by the spiritual concept of consciousness, as this necessitates that a person is able to communicate in order to explain that they are self-aware. It would then be perverse to suggest that someone unable to communicate, whether having not learnt to talk, or having lost the ability to communicate, is lacking consciousness, and no longer alive.
Even with the medical definition, which is based upon response to stimuli, people who are asleep are lacking consciousness.
I don't really understand what you're getting at about consciousness in this argument, really. I've not heard it used as a qualifier for the distinction between foetus and baby, because of course, consciousness is not a constant presence in the living.
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