The Constitution is the ultimate law, so the constitutional amendment is the ultimate way to change things. Where FOCA wants to codify what the Supreme Court says is in the Constitution, these amendments want to change the Constitution to make the Court say something else. Since Roe v. Wade held that the unborn were not constitutional persons and therefore had no rights to balance against a mother, an amendment bestowing a "right to life" or 14th Amendment personhood upon the unborn would Constitutionally prohibit abortion on demand as a matter of equal protection.
There have been many such amendment's proposed, but none have been passed by Congress.
See a 14th Amendment personhood type.
And a simple right to life style amendment.