The same arguments for abortion can and were used to justify slavery:
A fetus isn't a person. A negro isn't a person
If you don't like abortion, then don't have one. - If you don't like slavery, don't own a slave.
I'm personally against abortion, but I support others' right to choose to have one. I'm personally against slavery, but I support others' right to choose to own one.
There is no choice, when one option is moral evil.