this issue has been an evolving one...again, from Prof. Tribe's book "Abortion: The Clash of Absolutes"...
"But the traditional Catholic position on abortion - similar to that taken by Aristotle and by some rabbinic scholars in the Jewish tradition - was that a fetus was not a human being until the time of "animation." Under Catholic doctrine, male fetus became "animated" - that is, infused with a soul - at forty days after conception. A female fetus was believed to become animated at a gestational age of eighty days.
Although Catholicism traditionally forbade even early abortion, such abortion was condemned in essentially the same way that the church condemned, and continues to condemn, masturbation and contraception. It held that these acts interfered with the procreative purpose of sexual activity; but a fetus was not considered a person early in pregnancy, and early abortion wan not deemed homicide.
Only in the late nineteenth century, following the discovery of fertilization, did the debate about abortion within the church tip in favor of its now familiar position that human life begins at conception. I
This shift was given a strong push by the theological acceptance of the Immaculate Conception of Mary, not to be confused with the doctrine of the Miraculous Conception, Mary's pregnancy with Jesus. In 1701 Pope Clement XI declared the Immaculate Conception a feast of universal obligation. In 1854 Pius IX incorporated into Catholic dogma the teaching that Mary was without sin from the moment of her conception. These beliefs were not easily squared with the view that the fetus did not acquire a soul until later in pregnancy.
It was only in 1869 that Pius IX promulgated the papal enactment "Apostolicace sedis", which abandoned the limitation under which excommunication was to be imposed only for those abortions of "ensouled" fetuses. (This strict rule had first been in effect for two years in the late sixteenth century. The papal bull that contained the original declaration, "Effraenatam", was issued by Pope Sixtus V in 1588. But it did not gain acceptance with contemporary theologians and ti was repealed two years later by the new pope, Gregory XIV) Only at this point, well after the movement to criminalize abortion was under way in America, and only by implication, was the groundwork laid within the church for the theological position that all abortion is homicide."
So, all that being said, the Catholic Church's position has evolved since Jesus' time...and as Renee Roden has stated, the issue of "Personhood" is one of "Faith" and one that we as Catholics should strive to acknowledge...BUT...this is not the "United Catholic States of America", so we MUST NOT impose our beliefs on others who in all honesty do not share them. Frankly, it bothers me that all the SCOTUS Justices opposing Roe v. Wade are Catholics, and given the overwhelming number of Americans who believe abortion should be legal across the country for at least some cases, any overturning of Roe v. Wade could produce serious "blowback" against the Church for such a blatant display of insensitivity to other perspectives in a pluralistic, democratic society.