Plan B and the Doctrine of Double Effect

Some opponents of abortion claim that emergency contraception, labels notwithstanding, is not merely contraceptive but also abortifacient in effect. Based on this, they conclude two things. They conclude, first, that taking emergency contraception is morally equivalent to intentionally procuring an abortion, and thus impermissible.¹ And second, they claim that health care providers who sincerely object to abortion have a right to refuse to participate in the provision of such contraception.²

Supporters of emergency contraception question both claims. Against the first, some argue that the medications in question cannot possibly have an abortifacient effect because they do not stop a pregnancy.³ Against the second, some object that, while such "conscience clauses" are an understandable attempt to respect the rights of medical providers, they would do so at the cost of patients' rights to obtain necessary medical treatment.⁴

In what follows, I raise a different issue. Suppose that emergency contraception works exactly as its opponents claim. Would it follow that taking emergency contraception is morally equivalent to intentionally procuring an abortion? Perhaps surprisingly, I shall argue that it would not. If one accepts the doctrine of double effect, there would be circumstances in which the former is permissible even if the latter is never permissible.

Emergency Contraception: Contraceptive or Abortifacient?

First, a word of clarification. The term emergency contraception can refer both to various hormonal medications and to the insertion of an IUD after sex. In what follows, I will use the phrase "emergency contraception" to refer only to the various forms of hormonal emergency contraception. Plan B, the most common emergency contraception sold in the United States, is a progestin-only form of emergency contraception. Certain forms of hormonal birth control that contain both estrogen and progestin can also be used as emergency contraception when taken in larger than usual doses. Emergency contraception, as I will use the term, refers to both.

The exact mechanism by which hormonal forms of emergency contraception work is not well understood. The primary mechanism seems to be inhibiting ovulation. But failing this, they may also prevent fertilization or impair the implantation of a fertilized egg in the uterus. Such medication may be toxic to sperm, which would interfere with fertilization. And it also causes minor changes in the endometrium. Whether the changes are sufficient to prevent implantation is not known; several studies suggest they are not. But definitive proof either way is unavailable at present.⁵

This last (possible) mechanism is the source of the controversy. Opponents argue that if there are cases in which (1) the first two mechanisms fail, (2) fertilization occurs, and (3) the changes in the endometrium prevent the fertilized egg in question from implanting, these cases constitute abortions. Of course, if the medication functions as hoped, then there will be no fertilized egg and no abortion. And we may never know, in any particular case, what exactly has occurred. But on their view, that does not absolve us of responsibility for the cases in which an abortion does occur, and the fact remains that emergency contraception should be counted as an abortifacient.

Supporters of emergency contraception have responded in at least two ways. Some have argued that, even if emergency contraception functions exactly as its opponents fear, it could not possibly cause an abortion. The longstanding consensus in the medical community is that pregnancy begins when a fertilized egg implants itself in the uterus.⁶ And everyone agrees that emergency contraception cannot cause the termination of a fertilized egg that has already implanted itself in the uterus. Supposing that abortion is the deliberate termination of pregnancy, they conclude that emergency contraception cannot possibly cause an abortion.⁷

This is not a very promising line of thought. If someone opposes abortion on the grounds that a fetus is a person from the moment of conception, what he objects to is the destruction of that fetal life. The ending of a pregnancy, per se, is not the object of moral concern. For those who believe that personhood begins at conception, the key question is whether emergency contraception brings about the destruction of an already...