I think you'll find that astronomers and planetary scientists will say that evidence of water on Mars shows that it capable of supporting life, and that there is proof of life in the frozen water on Mars.
I don't think I've ever heard anything come out of a scientific journal (and I've subscribed to three) that says water is life.
Furthermore, the argument isn't about whether or not the tissue is alive. It's very firmly much alive. In the same way as an amoeba or a cow is alive.
I've often found the pro-lifers are actually amazingly ignorant of pre and post natal development and physiology, specifically neurogenesis.
The core of the argument is over whether it's a sentient organism prior to its birth, and generally, prior to the 24 week point that most medical people believe to be the point at which the lungs have developed enough for conversion of breathable air to waste gas (completely irregardless of how much of the brain and nervous system has formed).
Now, whilst measurable activity in the brainstem has been observed to happen as early as 54 days in some rare cases, this is notto beconfused with a developed brain.
The areas of the brain that control personality traits and intellectual function, predominantly the frontal lobes, is generally the last thing to develop, and isn't even fully developed at birth (allowing the skull to be squishy enough for the baby's head to squeezed out). Fuck, the Thalamic section of the brain doesn't even form until about week30, which means that there's actually no way that any sensory input can actually be used by whatever parts of the brain DO exist at that point.
IMO, a new born infant still has now personality and limited intellectual capacity that's actually below that of most animals... so if I don't know them, in the same way that I don't know the cow that was in my breakfast sandwich, what's the difference?