Couldn't a priest always absolve the sin of abortion of a truly repentant woman? I have heard the term "reserved" sins, is abortion one of those?
Never having had to seek forgiveness for that particular sin I don't know the answer.
Unless I'm mistaken, except in danger of death, certain sins are reserve to the pope, as for example, a priest breaking the seal of confession. Others, such as the sin of abortion, are reserved to the local ordinary, or a priest that he gives faculties to.