The penalty of automatic excommunication applies to anyone who deliberately chooses and accomplishes a direct abortion, with knowledge of the penalty attached.
Can. 1398 A person who procures a completed abortion incurs a latae sententiae excommunication.
This penalty applies to any direct abortion, accomplished in any manner, at any time from the moment of conception, as the Pontifical Commission for the Authentic Interpretation of the Code of Canon Law and the Pope clarified:
D. Utrum abortus, de quo in can. 1398, intelligatur tantum de eiectione fetus immaturi, an etiam de eiusdem fetus occisione quocumque modo et quocumque tempore a momento conceptionis procuretur.
R. Negative ad primam partem; affirmative ad secundam. (Source)
D. [doubt] Whether the abortion, to which Canon 1398 [refers], is to be understood  only concerning the expulsion of the immature fetus, or  also to the killing of the same fetus being procured in any manner, and at any time, from the moment of conception.
R. [response] Negative to the first part; affirmative to the second [part].
Pope John Paul II, in an audience on May 23, 1988, approved the above response. The Holy See has therefore ruled that any [direct and voluntary] killing of a prenatal, at any time from conception and in any manner, is the type of abortion that falls under the sentence of automatic excommunication in Canon 1398.
The first part of the Dubium (D.) asks if the abortions that incur excommunication under Canon 1398 are to be understood as only surgical abortions. This is phrased as the removal (or expulsion) of the immature (non-viable) fetus. Obviously, the removal of a viable fetus is either a natural child-birth or a C-section, not an abortion. The phrasing used is somewhat delicate, but nevertheless clear. The question is whether only a procured completed surgical abortion is the subject of Canon 1398 and excommunication. The Response says “Negative to the first part,” indicating that this type of abortion is NOT the only type that can incur excommunication under that Canon.
What types of direct abortion incur automatic excommunication? All types.
The second part of the Dubium asks if, instead of only surgical abortions, any manner of direct and deliberate killing of a fetus is the subject of Canon 1398 and excommunication. The Response says “affirmative to the second [part]”. Therefore, any intentionally-chosen means whatsoever of killing a prenatal human person, at any time from conception, is a direct abortion and incurs the penalty of automatic excommunication.
The issue here concerns abortifacient contraception and so-called emergency contraception. Both of these types of chemical interventions have two possible effects. The first is to prevent conception altogether; if no prenatal human person is conceived, then there is no issue of killing a prenatal. The penalty of excommunication for abortion does not apply to mere contraception. However, the deliberate choice of any type of contraceptive act, whether as a means or as an end, is a grave sin.
The second possible effect is to kill the prenatal after conception, typically (but not solely) by preventing implantation. This type of so-called “contraception” is truly a type of abortion, that is, a type of murder. The choice to use any abortifacient type of contraception is the grave sin of abortion as well as the grave sin of contraception.
The decision of the Holy See concerning Canon 1398 means that anyone who chooses to use abortifacient contraception, knowing that it is able to cause an abortion and knowing the penalty for such an act of direct abortion, is automatically excommunicated from the Church. Someone who used abortifacient contraception without knowing that it is abortifacient, or without knowing of the penalty of automatic excommunication for that sin, would not be excommunicated.
However, the use of contraception and the choice of direct abortion are each intrinsically evil and gravely immoral acts. They are each objective mortal sins, and if either or both are committed with full knowledge of the grave immorality of the act and with full deliberation, then each is an actual mortal sin, depriving the soul of the life of grace and deserving eternal punishment in Hell.
Does this penalty of automatic excommunication for the use of abortifacient contraception apply only to women? No, it is not limited to women. Concerning this penalty for abortion, Pope John Paul II wrote (in 1995, years after approving this decision of the Holy See in 1988) the following:
“The excommunication affects all those who commit this crime with knowledge of the penalty attached, and thus includes those accomplices without whose help the crime would not have been committed.” (Evangelium Vitae, n. 62).
If a husband knows that his wife is using abortifacient contraception, and he approves of this use and has marital relations with her, knowing that these sexual acts are contracepted and may result in an early abortion, and if he knows of the penalty for this type of abortion, then he too is automatically excommunicated. He is, at the very least, an accomplice in the grave sins of contraception and abortion. Perhaps he is more accurately considered to be a co-perpetrator.
Is it true that the use of abortifacient contraception is not the deliberate choice of abortion, that it is neither the sin of abortion, nor the type of act that would incur the penalty of automatic excommunication, based on the fact that the woman cannot know, on any particular occasion, whether the contraceptive method is acting as a contraception or as an abortifacient? No, it is not true.
This type of knowingly chosen act, choosing to use abortifacient contraception, has two evil moral objects: the deprivation of the procreative meaning from sexual acts (the moral object of contraception), and the deprivation of life from an innocent (prenatal) human person (the moral object of abortion). What makes an intrinsically evil act immoral is not the attainment of the moral object, but the deliberate (intentional, voluntary) choice of that inherently disordered act.
For example, if a couple choose to use contraception, but the method fails and they conceive a child, they are still guilty of the sin of contraception. They deliberately chose the type of act that is inherently directed toward the end of preventing conception. The attainment of that end is not what makes the act intrinsically evil, but rather the intrinsic ordering of the intentionally-chosen act toward an evil end.
Conversely, if a married couple are infertile, but they have natural marital relations open to life, they have not committed the sin of contraception. They chose the type of act inherently ordered toward the threefold good moral object of sexual acts: the marital, unitive, and procreative meanings. The failure to attain the procreative end of sexual relations does not change the inherent ordering of the act toward that good end.
In another example, if a person chooses to murder an adult by means of poison, he commits the sin of murder, even if the poison happens, by chance, not to kill that person. Or if a person chooses to give a poison to an adult, knowing that the poison has two possible effects, to harm the adult without killing or to kill him, then the choice of that act is still a type of murder.
So a woman who chooses to use abortifacient contraception, knowing that it is contraceptive, thereby chooses the grave sin of contraception, and knowing that it is abortifacient, thereby chooses the grave sin of abortion. One and the same act can have more than one moral object. For example, the grave sin of adultery has two evil moral objects: that the act is non-marital and that the act offends against the marital vows. So the grave sin of using abortifacient contraception is the deliberate choice of both types of sin: contraception and abortion. Therefore, the penalty for deliberately choosing a direct abortion also applies to this grave sin.
Is it true that a woman can morally choose to use contraception, if she does not have a contraceptive intention? Can she, for example, choose to take a contraceptive pill, for a medical purpose and while she is sexually active, justifying this act by the good intention of treating a medical disorder?
The answer to both questions is “No”. The Magisterium teaches that actions which are in themselves (that is, by their nature and condition) ordered toward a contraceptive end are absolutely forbidden. The Magisterium teaches that what makes any act moral or immoral are the three fonts of morality:
(1) intention (the purpose for which the act was chosen)
(2) moral object (the end toward which the act itself is inherently ordered)
(3) circumstances (the reasonably anticipated good and bad consequences)
To be moral, all three fonts must be good. Any act with one or more bad fonts is a sin; it is always immoral to knowingly choose an act with a bad font. Any act with an evil moral object is an intrinsically evil act; it is immoral by the very nature of the act, regardless of intention and circumstances.
A good intention, such as a medical purpose or therapeutic intention, can never justify an act with an evil moral object. Therefore, a non-contraceptive intention does not make the choice of this type of act, to use a contraceptive while the person is sexually active, moral. The deliberate choice of this type of act is the choice of an inherently disordered act. No intention or purpose can justify an act that is inherently immoral.
Moreover, the use of abortifacient contraception (while a women is sexually active) includes the sin of direct abortion. The treatment of a medical disorder, or the lack of a contraceptive or abortive intention, or any intention or circumstances whatsoever, cannot justify these two grave sins: abortion and contraception. If a woman uses abortifacient contraception while sexually active, she is choosing to contracept her sexual acts and to murder her own prenatal children. No purpose, however good, and no circumstance, however dire, can justify these mortal sins.
If she needs to take the birth control pill as a treatment for a medical disorder, she can do so morally if she refrains from all sexual acts. There is no medical need to have sexual relations. If she chooses to do both, to take an abortifacient and to have sexual relations, she is choosing the sins of contraception and abortion. The deprivation of the procreative meaning and the deaths of her unborn children are not “unintended side effects” or “unintended consequences”. For she is able to refrain from sexual relations while taking the pill; or she can have marital relations and decline to take the pill. The deliberate choice to do both is not unintended. The intended end, to treat a medical disorder, is distinct from the intentional choice of a type of act that is intrinsically ordered toward contraceptive and abortive ends. The latter is the intentional choice of an intrinsically evil act.
The deaths of her prenatal children, due to abortifacient contraception, are not justified by the principle of double effect. That principle can never justify any intrinsically evil act. It can only justify an act which has only good intentions AND only good moral object(s) IF the reasonably anticipated good consequences outweigh any reasonably anticipated bad consequences. The evil moral objects of contraception and abortion make such an act intrinsically evil and always gravely immoral. And the bad consequences of the deaths of one or more prenatal children, as she uses abortifacient contraception over a period of time, certainly outweigh the good of being able to continue to have marital relations.
The use of contraception for any intention or purpose, in any circumstances, is intrinsically evil and always gravely immoral. Direct abortion, for any intention or purpose, in any circumstances, is intrinsically evil and always gravely immoral. Neither contraception, nor direct abortion is ever justified by any end, since the end never justifies the means. The Magisterium has condemned contraception and abortion, whether as an end or a means.
Furthermore, the use of abortifacient contraception is the sin of contraception and the sin of direct abortion. Any Catholic who knowingly uses abortifacient contraception and anyone who is complicit in that sin as an accomplice, knowing that the penalty of excommunication applies to this and any other type of direct abortion, is automatically excommunicated.