It only prevents implantation when when it fails to prevent ovulation or kill sperm. This is a secondary side effect. Thus this is not the direct killing of an embryo anymore than removing the fallopian tube during an ectopic pregnancy emergency, which is considered morally licit.
MUA, this is a totally inaccurate comparison and not at all the same.
In the case of a tubal pregnancy, both the mother’s and baby’s life are in danger. The baby, with the medical technology we have now, has NO chance of survival, and his continued growth in the fallopian tube threatens greatly the life of the mother. Removing the problematic tube IS a morally licit course of action since it is not directly attacking the fetus. This is a course of action taken when two lives are in imminent danger, and the fetus is growing where it can’t survive. Regrettably, as it stands now, the fetus will not survive once removed, still in the problematic tube. This is a way that two people can be morally treated for an unfortunate abnormality that is life threatening.
There is no comparison to that of the rape victim. Her life is not in danger. Giving her the MAP is not a means of treating a disease or life threatening condition, it’s a means of preventing her from becoming pregnant.( that is unless you see pregnancy itself as a disease which is the common consensus) And, when that is done in a way that interrupts the implantation of an already conceived human life, that IS an abortion, and is not a morally licit course of action in the case of rape.
The only way the MAP can be licitly used is when there is certainly, through pregnancy and hormonal testing for ovulation, that there is NO potential for there already being a conception. It’s only to be used as a contraceptive, in the case of non consensual sex, ONLY.
And, it’s not completely inaccurate to say that the primary effect of the MAP is abortifacient, because it is, IF ovulation has occurred. After all, it can’t prevent ovulation if ovulation has already occurred, so that effect is moot. And, if there is already a conception, then it’s effect of killing sperm, is moot as well. So, you’re left with preventing implantation, which is abortion.