Do birth control pills cause abortions?

In order to prevent pregnancy, birth control pills employ several mechanisms. First, the synthetic hormones may convince a woman’s body that she is pregnant. This can stop the ovaries from releasing an egg. The Pill also makes it difficult for the sperm to reach the egg, because the hormones thicken the cervical mucus, making it difficult for the sperm to live and move. The Pill also creates changes in the uterus and fallopian tubes that can interfere with the transport of sperm.[1]

Despite the hormones’ ability to prevent the release of eggs, sometimes a “breakthrough ovulation” takes place. How often this happens depends upon several factors, such as which kind of pill the woman is taking, how consistently she takes her pills, and even how much she weighs. Even with correct and consistent use of the Pill, some formulas allow ovulation in less than 2 percent of cycles, while others allow a woman to ovulate during 65 percent of her cycles.[2]

When a woman ovulates, she can become pregnant. However, the Pill has mechanisms that can cause an abortion before a woman knows that she has conceived. If a sperm does fertilize the egg, the newly conceived baby (zygote) may be transported more slowly through the fallopian tubes because of how they have been altered by the Pill. Thus, the child may not reach the uterus, where he or she needs to implant and receive nourishment for the next nine months. Because the fallopian tubes are changed, the baby may accidentally implant there, causing an ectopic or “tubal” pregnancy, which is fatal to the baby, and can also be life-threatening for the mother.

If the baby is able to travel safely to the uterus, he or she may not be well received. One reason for this is that the chemicals in the Pill thin out the lining of the woman’s uterus (the endometrium).[3] As a result, the baby may not be able to implant. At other times the child will attach to the wall, but he or she will be unable to survive because the normally thick and healthy uterine wall has shriveled and is therefore unable to nourish the baby. The Pill also impacts the woman’s progesterone level. This causes the lining of the uterus to break down and eventually shed as it would in a menstrual cycle, further denying the baby’s attempt to implant.

Many doctors are concerned about the fact that women often are not informed that the birth control pill can cause an abortion as well as prevent pregnancy. One medical journal declared, “If any mechanism of any OC [Oral Contraceptive] violates the morals of any particular woman, the failure of the physician or care provider to disclose this information would effectively eliminate the likelihood that the woman’s consent was truly informed and would seriously jeopardize her autonomy. Furthermore, there is a potential for negative psychological impact on women who believe human life begins at fertilization, who have not been given informed consent about OCs, and who later learn of the potential for postfertilization effects of OCs. The responses to this could include disappointment, anger, guilt, sadness, rage, depression, or a sense of having been violated by the provider.”[4]

Unfortunately, not all doctors are aware that the Pill can act as an abortifacient. Dr. Walter Larimore admitted that he prescribed the Pill for nearly twenty years—and used it in his own marriage before anyone informed him that it could have such an effect.

When another doctor clued him in, he said that he had never heard of such a thing, and that the claims seemed to be “outlandish, excessive, and inaccurate.”[5] He began a review of the medical literature, “to disprove these claims to my partner, myself, and any patients who might ask about it.” However, what he discovered compelled him to stop using the Pill in his medical and personal life. Reviewing the information, he realized how many doctors (and patients) were ignorant of the abortifacient potential of the Pill. It was a humbling realization, considering that ever since the 1970s, the patient package insert for birth control pills explained how the drug reduces the likelihood of implantation.[6]

After informing his colleagues, Dr. Larimore noted, “several said that they thought it would change the way family physicians informed their patients about the Pill and its potential effects.”[7] Because many physicians felt that it was unfair to leave women in the dark, some of them submitted a proposal to the American Medical Association (AMA) calling for a vote on whether doctors should tell patients that birth control pills can act as abortifacients. However, in 2001 the AMA voted overwhelmingly against the proposal.

One reason why certain doctors may not tell women about the abortifacient nature of the Pill is that some physicians do not believe that pregnancy begins with fertilization. Until the 1960s, when the Pill was invented, it had been taken for granted that the union of the sperm and egg signaled the beginning of pregnancy. In 1963 even the United States government published health information declaring that anything that impairs life between the moment of fertilization and the completion of labor is to be considered an abortion.[8]

Because many women would never have agreed to use a drug or device that could cause an early abortion, those in favor of such contraceptives knew that the issue had to be resolved. In 1964 a Planned Parenthood doctor speaking of another type of abortifacient birth control recommended that scientists not “disturb those people for whom this is a question of major importance.” He added that judges and theologians trust the medical community, and “if a medical consensus develops and is maintained that pregnancy, and therefore life, begins at implantation, eventually our brethren from the other faculties will listen.”[9]

One year later the American College of Obstetricians and Gynecologists (ACOG) decided to redefine pregnancy. In its words, “conception is the implantation of a fertilized ovum.”[10] Instead of defining conception as fertilization, ACOG decided that life begins nearly a week later, at implantation. At the time they said that this was because pregnancy could not be detected before then. Today science is able to detect pregnancy before implantation, but the ACOG still won’t correct its definition.[11] The original change had nothing to do with a scientific discovery in women’s health, reproduction, or biology. Unfortunately, doctors today are split on the issue.[12]

Regardless of a doctor’s personal opinions, few women are ever informed about this issue. Feminist author Germaine Greer wrote, “Whether you feel that the creation and wastage of so many embryos is an important issue or not, you must see that the cynical deception of millions of women by selling abortifacients as if they were contraceptives is incompatible with the respect due to women as human beings.”[13]

[1]. Walter L. Larimore and Joseph B. Stanford, “Postfertilization Effects of Oral Contraceptives and Their Relationship to Informed Consent,” Archives of Family Medicine 9 (February 2000), 127.
[2]. Larimore and Stanford, 127.
[3]. Physicians’ Desk Reference (Montvale, N.J.: Thomson, 2006), 2414.
[4]. Larimore and Stanford, 131.
[5]. Larimore and Stanford, 133.
[6]. Federal Register 41:236 (December 7, 1976), 53,634.
[7]. Larimore and Stanford, 133.
[8]. Public Health Service Leaflet no. 1066, U.S. Dept. of Health, Education, and Welfare (1963), 27.
[9]. Sheldon Segal, ed., et al., “Proceedings of the Second International Conference, Intra-Uterine Contraception,” October 2–3, 1964, New York City, International Series, Excerpta Medica Foundation, No. 1 (September 1965).
[10]. College of Obstetricians and Gynecologists, “Terms Used in Reference to the Fetus,” Terminology Bulletin 1 (Philadelphia: Davis, September 1965).
[11]. Shu-Juan Cheng, et al., “Early Pregnancy Factor in Cervical Mucus of Pregnant Women,” American Journal of Reproductive Immunology 51:2 (February 2004), 102–105.
[12]. J.A. Spinato, “Informed Consent and the Redefining of Conception:
A Decision Ill-Conceived?” The Journal of Maternal-Fetal Medicine 7:6 (November-December 1998), 264–268.
[13]. Germaine Greer, The Whole Woman (New York: Anchor Books, 1999), 99.

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