Jim Sedlak, vice president of the American Life League, outlined this position in an email responding to my inquiry:

Every human being begins life at Stage 1a — the beginning of the process of fertilization. According to the manufacturer, one of the methods of operation of the IUD is to prevent implantation of an already created human being. This results in the death of that human being. Most reasonable people recognize this as an abortion. The morning after pill is basically a megadose of regular birth control pills. The manufacturers of these products state that they work some of the time by inhibiting implantation. Thus, yes, it is an abortifacient.

By this logic, a presidential candidate seeking to live up to the standards set by Sedlak and others in the anti-abortion community must then agree that the IUD and morning after pill cause abortions.

The American College of Obstetricians and Gynecologists disputes this argument. Instead of addressing the question of when life begins, it maintains in a paper, “Emergency Contraception and Intrauterine Devices are Not Abortifacients,” that “pregnancy is established only at the conclusion of implantation of a fertilized egg.” In other words, contraceptive devices that act before implantation do not end a pregnancy because the pregnancy has not begun.

The Department of Health and Human Services has a similar definition of pregnancy: “Pregnancy encompasses the period of time from implantation until delivery.”

The Food and Drug Administration has approved 20 contraceptive methods, from male condoms to spermicides. Strict abortion opponents object to four of the 20 — two “morning after pills,” Plan B and Ella, and two intrauterine devices, ParaGard and Mirena — in the belief that these methods prevent eggs that have been successfully fertilized by sperm from implanting on the wall of the uterus.

On June 30, 2014, in the Hobby Lobby decision, the Supreme Court ruled that since “owners of three closely held for-profit corporations have sincere Christian beliefs that life begins at conception and that it would violate their religion to facilitate access to contraceptive drugs or devices that operate after that point,” these companies may refuse to provide coverage for these four means of contraception.

There is disagreement about whether IUDs interfere with the implantation of a fertilized egg. The University of Michigan health care site, designed to provide comprehensive information to college students and faculty, says “Both types of IUD prevent fertilization of the egg by damaging or killing sperm. The IUD also affects the uterine lining (where a fertilized egg would implant and grow),” adding that the copper IUD “makes the lining a poor place for a fertilized egg to implant and grow.” The Columbia University website addressing the question “How does an IUD work?” states that

The exact mechanisms are not fully understood, but the IUD may work by stopping sperm from reaching the egg or by changing the lining of the uterus to prevent a fertilized egg from attaching to the uterus wall.

I wrote Kate Connors of the American College of Obstetricians and Gynecologists to ask, “What does ACOG say about the contention of pro-lifers that IUDs can prevent implantation of a fertilized egg?”