You misstate the Roman Catholic position here. It is NOT an abortion to remove an ectopic pregnancy that is threatening a woman’s life. “Abortion” is a term that refers to killing the unborn baby specifically for the sake of depriving it of life. In an ectopic pregnancy, it is reasonable to remove it when there is NO chance that it will survive and NO other chance of the mother’s survival. In that case, the baby is not being deliberately killed, but is an unwanted and unavoidable result of saving the mother. There are currently efforts being made to find a way to safely ‘reimplant’ an ectopic pregnancy in the healthy tissue of the uterus, and when that happens, deliberately killing an ectopic pregnancy will be logically reclassified as an abortion, but with the state of medicine at this time, it isn’t.
