This is cherry picking at its extreme. The passage reads: "Lev 17:11 For the life of the flesh is in the blood, and I have given it for you on the altar to make atonement for your souls, for it is the blood that makes atonement by the life."
First, 'blood is life' is true enough. But how that can be construed that life only begins at birth is absurd. Does a fetus miraculously acquire blood at the moment of birth? Of course not. Blood is intrinsic in a fetus' development. Therefore if blood is a quantifier for life (their argument), a fetus has life in the womb.
But that is still a straw-dog argument. The passage selected has nothing to do with conception, babies, fetuses, or anything to do with human form. It is a commandment from God on the use of animal sacrifices, and an admonition to man not to eat or drink blood for the condemnation it brings: "Lev 17:14 For the life of every creature is its blood: its blood is its life. Therefore I have said to the people of Israel, You shall not eat the blood of any creature, for the life of every creature is its blood. Whoever eats it shall be cut off."
I've been accused of cherry picking passages that suit my viewpoint while ignoring the one that is important in the life cycle of a fetus - child - adult. Yeah, right. And by the cherry-picker extremist no less.
Waste no more time on this tool. He's not worth the effort.
Now you want to define life differently than what the Bible does, fine with me.