The question is not whether a foetus (foitos: "little one" in classical Greek) is "viable"; but whether it is alive.
Science proves that a foetus is alive, from the outset. And how alive ? - as a human being, not as some mythical sort of human acorn.
Most atheists fit the bill; though, very predictably, deny the fact !
It isn't the purpose of religion to discern how the universe works (which is why science and religion aren't in conflict, because they aren't in competition) - the purpose of religion is to discern whether the universe has...
History has taught this no less to believers - witness the vast number of Christians, killed for no other reason than their Christian belief, in the Darkest and bloodiest of all centuries, the wonderfully-modern 20th.
But in the case of God's existing, you could know He exists if you WANTED to ! And you DO know that Jesus exists !
If Jesus had a massive ego, He wouldn't have died a terrible and humiliating death on the cross to save each of us from Hell.
Well, I can - the universe; proof of God's existence except to those who are wilfully blind.
You seem to be worshipping our five senses (as enhanced by scientific instruments) - which is an idolatrous worship of the human brain.
Please don't say: if we and science can't perceive something, it...
Epicurus chose to overlook reality - that God has delegated freewill to His angelic and human creations, thus (temporarily) surrendering part of His omnipotence.