To be clear, I am pro choice so I disagree with their conclusion. But I don't think life is special.
Most things we eat were once alive. Salt is a rock and was never alive. A lot of fruit can be eaten without killing the plant it came from. But every time you eat a carrot, a plant was killed for you. Following the form of the anti abortionists' argument, that carrot plant was murdered for you.
Every time you take antibiotics for an infection or use vinegar on a cutting board you kill things that had been alive.
I don't mourn when I bleed, even though blood cells that share my DNA die. Nor do I morn when I give a blood sample to get my cholesterol checked.
So arguing that abortion is murder because life begins at conception is hypocritical even for anti abortionists who are vegetarian and don't kill spiders.