“Show me a single situation where a mother’s life is in danger, and only abortion will save her”.
The only exception that I could see is an ectopic pregnancy. Some can debate it is an abortion; however, I would disagree. For one, the fetus is usually deformed beyond any sort of viability. Secondly, it can’t be transplanted into the uterus. Third, the fetus will die no matter what so the surgery is done to prevent the death of the Mother as well. That is the only case that I can think of and it shouldn’t be banned.
In a Ectopic pregnancy, the doctor performing the procedure is not killing the child. It is a necessary medical procedure to save the mother. That is not considered the willful taking of a life, and that is the position of the Catholic Church, which does not believe in abortion under any circumstance.
Abortion is always evil - it intends to directly kill a child. It is never allowed even to save the life of the mother. The Church clearly teaches that One may never do evil so that good may result from it (Catechism, 1789).
However, in the case you describe, the mothers malfunctioning organ (fallopian tube, or a portion of it), may be morally removed to eliminate the risk to the mother. The intent here is to remove an organ that is about to rupture (no different than if a tumor was there). To not do so would be life threatening to the mother. It is unfortunate that the threat happens to be caused by an abnormal pregnancy. If the child dies his or her death is not directly intended but is tolerated as an unintended consequence. (In the future it might be possible to implant such a child into the uterus. Until such time, however, the procedure is still moral.)
http://forums.catholic.com/showthread.php?t=17307
You are right. This surgery is not rationally referred to as “abortion” however.