Let's see if I can explain it this way. I don't give a damn if it's called a "life" or not. As long as it's inside another person's body it is part of that body to the extent the host body makes all the decisions.
Maybe an analogy will help. Let's say 18 is the age of majority. Until a person is 18 they have to respect their parent's decisions. Even when they are 17 and 364 days old they are not adults. What happens the day they turn 18? Not much physically. It's merely a designated line. If a parent can not, or refuses to, look after their child they can have the child removed from the home. No court is going to insist on the child staying there.
The same idea applies to abortion. The parent is not demanding the fetus be killed. The parent is demanding the fetus be removed. The parent's right, the right to their own body, (to coin a popular phrase) shall not be infringed. A life? A human being? A fetus? Call it what you will. Just remove it.