The Pill is the popular term for more than forty different commercially available oral contraceptives. In the medical field, they are commonly referred to as BCPs (Birth Control Pills), OCs (Oral Contraceptives), and/ or OCPs (Oral Contraceptive Pills).
The Pill is used in America by about fourteen million women each year. Across the globe, it is used by hundreds of millions. The question of whether it causes abortions has a direct bearing on untold millions of Christians, many of them pro-life, who use it and recommend it. For those who believe that God is the creator of each person and that He is the giver and taker of human life, this is a question with the most profound moral implications. A great deal is at stake here not simply for society, but for the church of Jesus Christ.
After coming to grips with the importance of this issue, and hearing conflicting opinions for the last few years, I determined to thoroughly research this question and communicate my findings, no matter what they might be.
I wanted, and still want, the answer to this question to be "No." I came to this issue as a skeptic. Though I heard people here and there make an occasional claim that the Pill caused abortions, I learned long ago not to trust everything said by sincere Christians, who are sometimes long on zeal but short on careful research.
While I'm certainly fallible, I have taken pains to be as certain as possible that the information I am presenting here is accurate. I've examined medical journals and other scientifically oriented sources -- everything from popular medical reference books to highly technical professional periodicals. I've checked and double-checked, submitted this research to physicians, and asked clarifying questions of pharmacists and other experts. A few of my citations are from pro-life advocates. Most are physicians, scientists, researchers, Pill-manufacturers and other secular sources. I am not a physician, but I am an experienced researcher. I have sought to put the most stock in sources that appear to be the most scientifically credible. (If I were conducting medical studies, obviously my not being a physician would disqualify me_but I am not doing medical studies, I am simply reading, collecting, and organizing them for this presentation.)
Because I want readers to be able to do what I did -- hunt down every original source you can and see it for yourself -- I have included full documentation and reference information directly in the text. I realize this may not feel "reader-friendly" to some, but it will keep the reader from constantly having to turn to an endnotes section to see what source is being cited. (I have sometimes put in boldface type certain quoted phrases I wish to emphasize -- these are not boldfaced in the originals.)
Before going further, let me affirm a truth that is a foundational premise of all I am about to address: each human being is created by God at the point of conception. This is the clear teaching of the Bible and is confirmed by scientific evidence. If you are not completely convinced of this, please stop now and read the first two appendices. They both answer the question, "When Does Human Life Begin?" Appendix A gives the answer of Scripture and Appendix B the answer of science. You may also wish to read the other appendices to bring a biblical perspective to the importance of the issue dealt with in this booklet.
(Because there is so much at stake, and because there is a great spiritual battle surrounding this issue, I ask the reader to pause and pray, asking God to give you his mind and heart concerning what we are about to deal with.)
Contraceptives are chemicals or devices that prevent conception. A birth control method that kills an already conceived person is not a contraceptive, it is an abortifacient.
The problem of "contraceptives" that are really abortifacients is not a new one. Pro-life Christians have long opposed the use of Intra-Uterine Devices (IUDs), because they do not prevent conception, but keep the already conceived child from implanting in his mother's womb. (A recent study challenges this understanding, but many prior ones support it.) Likewise, we oppose RU-486, the anti-progesterone abortion pill. RU-486 is a human pesticide, causing a mother's womb to become hostile to her own child, resulting in an induced miscarriage.
Depo-Provera is an anti-progesterone injected every three months. It sometimes suppresses ovulation, but also thins the lining of the uterus, preventing implantation. Norplant is another anti-progesterone drug enclosed in five or six flexible closed capsules or rods, which are surgically implanted beneath the skin. It often suppresses ovulation, but sometimes ovulation occurs, and when it does an irritation to the uterine wall often prevents implantation.
The Emergency Contraceptive Pill (ECP) also known as the "Morning After Pill" does not prevent pregnancy, but keeps a fertilized egg from implanting in the uterus.
All of these birth control methods either sometimes or often alter the mother's womb in a way that causes it to reject the human life which God designed it to nourish and sustain. Christians properly reject these methods because they know that human life begins at conception, six days before implantation begins. Therefore, anything that interferes with implantation kills a person created in the image of God.
These birth control methods are often referred to as "contraceptives," but they are not exclusively contraceptives. That is, they do not always prevent conception, but sometimes or often result in the death of already conceived human beings.
(The term "fertilized egg" is itself unfortunate and dehumanizing -- the truth is that both egg and sperm are in no sense human beings, but simply products of two human beings. At the point of fertilization, someone brand new comes into existence, with twenty-three chromosomes from the egg and twenty-three from the sperm combining into a never-before-existing and unique human being. As the sperm no longer exists, neither in essence does the egg, for it is replaced by a new creation with a unique DNA, rapidly growing and dividing on its own. This new human being is no more a mere "fertilized egg" than it is a "modified sperm." He or she is a newly created person, with not only gender but the equivalent of hundreds of volumes of distinct genetic programming.)
Progestin-only pills (which have no estrogen) are often called "minipills." (Many people confuse them with the more popular combination estrogen-progestin pills, which are the true "Birth Control Pill."
Drug Facts & Comparisons is a standard reference book for physicians. In the 1996 edition (page 419), it says this under "Oral Contraceptives":
Oral contraceptives (OCs) include estrogen-progestin combos and progestin-only products. Progestin-only [pills] . . . alter the cervical mucus, exert a progestational effect on the endometrium, apparently producing cellular changes that render the endometrium hostile to implantation by a fertilized ovum (egg) and, in some patients, suppress ovulation.
Note that progestin-only pills have a primary effect to make the uterine lining (endometrium) "hostile to implantation by a fertilized ovum." In other words, they cause abortion of a human being roughly a week after his or her conception.
I have been told that many users of the minipill erroneously think their ovulations are being suppressed. In his book, Gynecology: Principles & Practices (YearBook Medical Publishers, 3rd edition, 1979, page 735), R.W. Kistner says, "Certainly the majority of women using the progestin-only pill continue to ovulate."
In his book Hormonal Contraception: Pills, Injections & Implants, Dr. Joseph W. Goldzieher, states, "Endometrial resistance to implantation is an important mechanism of the minipill." (Essential Medical Information Systems, PO Box 811247, Dallas, Texas, page 35).
A 1981 Searle leaflet, packaged with their progestin-only pill, says that the product "makes the womb less receptive to any fertilized egg that reaches it."
The Physician's Desk Reference, 1996 edition (page 1872) describes "Progesten-Only Oral contraceptives" by saying they "are known to alter the cervical mucus and exert a progestational effect on the endometrium, interfering with implantation."
Clearly, the progestin-only pill, by its effects on the endometrium, causes abortions and must be added to the list of abortive birth control methods. Like all the aforementioned products, the changes the mini-pill creates in the mother's endometrium make the womb hostile to the newly conceived child, rather than hospitable to him, as God designed the mother's womb to be.
But what about the far more widely-used Birth Control Pill, with combined estrogen and progestin? Is it exclusively a contraceptive? That is, does it always prevent conception? Or does it, like these other products, sometimes result in abortions? That is the central question of this booklet.
To make the issue more personal, I'll share my own experience. In 1991, while researching my book Pro-life Answers to ProChoice Arguments, I heard someone suggest that birth control pills can cause abortions. This was brand new to me -- in all my years as a pastor and a pro-lifer, I had never heard it before.
My vested interests were strong in that Nanci and I used the Pill in the early years of our marriage, as did many of our pro-life friends. Why not? We believed it simply prevented conception. We never suspected it had any potential for abortion. No one told us this was even a possibility. I confess I never read the fine print of the Pill's package insert, nor am I sure I would have understood it even if I had.
In fourteen years as a pastor, doing considerable premarital counseling, I always warned couples against the IUD because it causes abortions. I typically recommended young couples use the Pill because of its relative ease and effectiveness.
At the time I was researching Pro-life Answers, I found only one person who could point me toward any documentation that connected the Pill and abortion. She indicated just one primary source that supported this belief and I only came up with one other. Still, these two sources were sufficient to compel me to include this warning in my book:
Some forms of contraception, specifically the intrauterine device (IUD), Norplant, and certain low-dose oral contraceptives, often do not prevent conception but prevent implantation of an already fertilized ovum. The result is an early abortion, the killing of an already conceived individual. Tragically, many women are not told this by their physicians, and therefore do not make an informed choice about which contraceptive to use. . . . Among pro-lifers there is an honest debate about contraceptive use and the degree to which people should strive to control the size of their families. But on the matter of controlling family size by killing a family member, we all ought to agree. Solutions based on killing people are not viable. (Pro-life Answers to ProChoice Arguments, Multnomah Press, 1992, 1994, page 118).
In reference to the abortive potential of low-dose oral contraceptives, in my book I footnoted two articles, one "Investigational Contraceptives," in the May 1987 Drug Newsletter, page 34; the other the January 1990 "Contraceptive Technology Update," page 5.
At the time, however, I incorrectly believed that "low dose" birth control pills were the exception, not the rule, and that most people who took the Pill were in no danger of having abortions. What I've found in my recent research is that since 1988 virtually all oral contraceptives used in America are low-dose, that is, they contain much lower levels of estrogen than the earlier birth control pills. Danforth's Obstetrics and Gynecology (Philadelphia: J.B. Lippincott Co., 1994, 7th edition, page 626) says this:
The use of estrogen-containing formulations with less than 50 micrograms of estrogen steadily increased to 75% of all prescriptions in the United States in 1987. In the same year, only 3% of the prescriptions were for formulations that contained more than 50 micrograms of estrogen. Because these higher-dose estrogen formulations have a greater incidence of adverse effects without greater efficacy, they are no longer marketed in the United States.
After the Pill had been on the market fifteen years, many serious negative side effects of estrogen had been clearly proven (Nine Van der Vange, "Ovarian activity during low dose oral contraceptives," published in Contemporary Obstetrics and Gynecology, edited by G. Chamberlain; London: Butterworths, 1988, page 315-16). These included blurred vision, nausea, cramping, irregular menstrual bleeding, headaches, and increased incidence of breast cancer, strokes, and heart attacks, some of which led to fatalities.
Beginning in the mid-seventies, manufacturers of the Pill steadily decreased the content of estrogen and progestin in their products. The average dosage of estrogen in the Pill declined from 150 micrograms in 1960 to 35 micrograms in 1988. These facts are directly stated in an advertisement by the Association of Reproductive Health Professionals and Ortho Pharmaceutical Corporation in Hippocrates magazine, May/June 1988, page 35.
As of October 1988, the newer lower dosage birth control pills are the only type available in the U.S., by mutual agreement of the Food and Drug Administration and the three major Pill manufacturers: Ortho, Searle, and Syntex. (Oral Contraceptives and IUDs: Birth Control or Abortifacients?, November 1989, page 1.)
What has now been considered a "high dose" of estrogen is 50 micrograms, which is in fact a very low dose in comparison to the 150 micrograms once standard for the Pill? The "low dose" pills of today are mostly 20-35 micrograms. As far as I can tell (from looking them up individually in medical reference books), there are no birth control pills available today that have more than 50 micrograms of estrogen. If there are any, they are certainly rare.
Not only was I wrong in thinking low-dose contraceptives were the exception rather than the rule, but I also didn't realize there was considerable documented medical information linking birth control pills and abortion. Still more has surfaced in the years since.
I say all this to emphasize I came to this research with no prejudice against the Pill. In fact, I came with prejudice toward it. I certainly don't want to believe I may have jeopardized the lives of my own newly conceived children, nor that I was wrong in recommending it to all those couples I counseled as a pastor. It would take compelling evidence for me to change my position, but I resolved to pursue this research with an open mind, sincerely seeking the truth and hoping to find out the Pill does not really cause abortions. As we will now directly examine the evidence, I urge you to ask the Lord to give you a truth-seeking mind and an open heart.
The Physician's Desk Reference is the most frequently used reference book by physicians in America. The PDR, as it's often called, lists and explains the effects, benefits, and risks of every medical product that can be legally prescribed. The Food and Drug Administration requires that each manufacturer provide accurate information on its products, based on scientific research and laboratory tests. This information is included in The PDR.
As you read the following information, keep in mind that implantation, by definition, always involves an already conceived human being, and therefore any agent which serves to prevent implantation thereby functions as an abortifacient.
This is the PDR's product information as listed by Ortho, one of the two largest manufacturers of the Pill, under Ortho-Cept:
Combination oral contraceptives act by suppression of gonadotropins. Although the primary mechanism of this action is inhibition of ovulation, other alterations include changes in the cervical mucus, which increase the difficulty of sperm entry into the uterus, and changes in the endometrium which reduce the likelihood of implantation. (The PDR, 1995, page 1775).
The FDA-required research information on the birth control pills Ortho-Cyclen and Ortho Tri-Cyclen also state that they cause "changes in . . . the endometrium (which reduce the likelihood of implantation)." (The PDR, 1995, page 1782).
Notice that these changes in the endometrium, and their reduction in the likelihood of implantation, are not stated by the manufacturer as speculative or theoretical effects, but as actual ones. (The importance of this distinction will surface later.)
Similarly, Syntex, another major Pill manufacturer, says this in Physician's Desk Reference (1995, page 2461) under the "Clinical Pharmacology" of the six pills it produces (two types of Brevicon and four of Norinyl):
Although the primary mechanism of this action is inhibition of ovulation, other alterations include changes in the cervical mucus (which increase the difficulty of sperm entry into the uterus), and the endometrium (which may reduce the likelihood of implantation).
Wyeth, on page 2685 of The PDR, 1995, says something very similar of its combination Pills, including Lo/Ovral and Ovral: "other alterations include changes in the cervical mucus . . . and changes in the endometrium which reduce the likelihood of implantation." Wyeth makes virtually identical statements about its birth control pills Nordette (The PDR, 1995, page 2693) and Triphasil (page 2743).
A young couple showed me their pill, Desogen, a product of Organon. I looked it up in The PDR (1995, page 1744). It states one effect of the pill is to create "changes in the endometrium which reduce the likelihood of implantation."
The inserts packaged with birth control pills are condensed versions of longer research papers detailing the Pill's effects, mechanisms, and risks. Near the end, the insert typically says something like the following, which I am quoting directly from the Desogen pill insert:
If you want more information about birth control pills, ask your doctor, clinic, or pharmacist. They have a more technical leaflet called the Professional Labeling, which you may wish to read. The Professional Labeling is also published in a book entitled Physician's Desk Reference, available in many bookstores and public libraries.
Of the half dozen birth control pill package inserts I've read, only one included the information about the Pill's abortive mechanism (a package insert dated July 12, 1994, found in the oral contraceptive Demulen, manufactured by Searle). Yet this abortive mechanism was referred to in all cases in the manufacturer's Professional Labeling, as documented in The Physician's Desk Reference. (Again, the full disclosure in the Professional Labeling is required by the FDA.)
If all this is repetitive, it establishes that according to multiple references throughout Physician's Desk Reference, which articulate the research findings of a variety of birth control pill manufacturers, there are not one but three mechanisms of birth control pills: 1) inhibiting ovulation (the primary mechanism), 2) thickening the cervical mucus, thereby making it more difficult for sperm to travel to the egg, and 3) thinning and shriveling the lining (endometrium) of the uterus to the point that it is unable to facilitate the implantation of the newly fertilized egg. While the first two mechanisms are contraceptives, the third is abortive.
When a woman taking the Pill discovers she is pregnant (according to The Physician's Desk References efficacy rate tables, listed under every contraceptive, this is 3% of pill-takers each year), it means that all three of these mechanisms have failed. Clearly then, this third mechanism sometimes fails in its role as backup, just as the first and second mechanisms sometimes fail. Each and every time the third mechanism succeeds, however, it causes an abortion.
As a woman's menstrual cycle progresses, her endometrium gradually gets richer and thicker in preparation for the arrival of any newly conceived child who may be there to attempt implantation. In a natural cycle, unimpeded by the Pill, the endometrium experiences an increase of blood vessels, allowing an increased blood supply to bring oxygen and nutrients to the child. There is also an increase in the endometrium's stores of glycogen, a sugar that serves as a food source for the blastocyst (newly conceived child) as soon as he or she implants.
The statements in The Physician's Desk Reference, and others to follow, testify that the Pill keeps the woman's body from creating the most hospitable environment for a child, resulting instead in an endometrium that is thin and depleted, deficient in both food (glycogen) and oxygen. This deficiency may result in the child's death by starvation and suffocation. (Scientifically, one does not have to have a stomach to starve or lungs to suffocate.)
Typically, the blastocyst (new person) attempts to implant six days after conception. If implantation is unsuccessful, she starves to death and is flushed out of the womb in an early miscarriage. (When the miscarriage is the result of an environment created by a foreign device or chemical, it is actually an abortion.)
The March 1996 issue of Fertility and Sterility presents significant research results, then states,
These data suggest that the morphological changes observed in the endometrium of OC users have functional significance and provide evidence that reduced endometrial receptivity does indeed contribute to the contraceptive efficacy of OCs [oral contraceptives]. (Somkuti, et al., "The Effect of Oral Contraceptive Pills on Markers of Endometrial Receptivity, Fertility, and Sterility, Volume 65, #3, 3/96, page 488.)
In an extensive study, Chowdhury & Joshi point to the diminished capacity of the endometrium as part of the effectiveness of the Pill ("Escape ovulation in women due to the missing of low dose combination oral contraceptive pills," Contraception, 1980; 22:241).
In a study of oral contraceptives published in a major medical journal Dr. G. Virginia Upton, Regional Director of Clinical Research for Wyeth International (one of the major birth control pill manufacturers), says this:
The graded increments in LNG in the triphasic OC serve to maximize contraceptive protection by increasing the viscosity of the cervical mucus (cervical barrier), suppressing ovarian progesterone output, and causing endometrial changes that will not support implantation. ("The Phasic Approach to Oral Contraception," The International Journal of Fertility, volume 28, 1988, page 129.)
Dr. Goldzieher (Hormonal Contraception, page 122) says as a result of the combined Pill's action "possibly the endometrium in such cycles may provide additional contraceptive protection. ' (Note that the author redefines "contraceptive," which historically meant something which prevents conception, yet is used here of preventing implantation of an already conceived person.)
The medical textbook Williams Obstetrics (Cunningham, et al, Stamford, CT: Appleton & Lange, 1993, page 1323) states, "Similar to estrogens, progestins produce an endometrium that is unfavorable to blastocyst implantation."
Drug Facts and Comparisons says this about birth control pills in its 1996 edition:
Combination OCs inhibit ovulation by suppressing the gonadotropins, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). Additionally, alterations in the genital tract, including cervical mucus (which inhibits sperm penetration) and the endometrium (which reduces the likelihood of implantation), may contribute to contraceptive effectiveness.
"The Pill: How does it work? Is it safe?" (The Couple to Couple League, PO Box 111184, Cincinnati, OH, 45211) states on page 4:
When the Pill fails to prevent ovulation, the other mechanisms come into play. Thickened cervical mucus may make it more difficult for the sperm to reach the egg: however, if the egg is fertilized, a new life is created. The hormones slow the transfer of the new life through the fallopian tube, and the embryo may become too old to be viable when it does enter the uterus.
If the embryo is still viable when it reaches the uterus, underdevelopment of the uterine lining caused by the Pill prevents implantation. The embryo dies and the remains are passed along in the next bleeding episode which, incidentally, is not true menstruation, even though it is usually perceived as such.
A standard medical reference, Danforth's Obstetrics and Gynecology (Philadelphia: J.B. Lippincott Co., 1994, 7th edition, page 626) states this: "The production of glycogen by the endometrial glands is diminished by the ingestion of oral contraceptives, which impairs the survival of the blastocyst in the uterine cavity."
In her article Abortifacient Drugs and Devices: Medical and Moral Dilemmas (Linacre Quarterly, August 1990, page 55), Dr. Kristine Severyn states,
The third effect of combined oral contraceptives is to alter the endometrium in such a way that implantation of the fertilized egg (new life) is made more difficult, if not impossible. In effect, the endometrium becomes atrophic and unable to support implantation of the fertilized egg. . . . the alteration of the endometrium, making it hostile to implantation by the fertilized egg, provides a backup abortifacient method to prevent pregnancy.
One of the things that surprised me in my research was that though many recent sources testify to the Pill's abortive capacity, it has been well established for more than two decades. The following eight sources were all written in the 1970s. (Keep in mind that the term "blastocyst" refers to the newly conceived human being -- "it" is not a thing, but a person, a "he" or "she."
Dr. Daniel R. Mishell of the USC School of Medicine said,
Furthermore, they [the combination pills] alter the endometrium so that glandular production of glycogen is diminished and less energy is available for the blastocyst to survive in the uterine cavity. ("Current Status of Oral Contraceptive Steroids," Clinical Obstetrics & Gynecology 19:4, December 1976, page 746.)
[While serving as] president of the Food and Drug Administration (FDA), Dr. J. Richard Crout said this of combination birth control pills:
Fundamentally, these pills take over the menstrual cycle from the normal endocrine mechanisms. And in so doing they inhibit ovulation and change the characteristics of the uterus so that it is not receptive to a fertilized egg. (FDA Consumer, HEW publication number 76-3024, reprinted from May 1976.)
In 1970, J. Peel and M. Potts's Textbook of Contraceptive Practice (Cambridge University Press, 1970, page 8) acknowledged,
In addition to its action on the pituitary-ovarian axis the combination products ["the Pill"] also alter the character of the cervical mucus, modify the tubal transport of the egg, and may have an effect on the endometrium to make implantation unlikely.
In their book Ovulation in the Human, P.G. Crosignani and D.R. Mishell (Academic Press, Inc., 1976, page 150), stated that birth control pills "alter the cervical mucus . . . as well as affect the endometrium, reducing glycogen production by the endometrial glands which are necessary to support the blastocyst."
The 1977 sixth edition of the Handbook of Obstetrics & Gynecology, then a standard reference work, states on pages 689-690,
The combination pill . . . is effective because LH release is blocked and ovulation does not occur; tubal motility is altered and fertilization is impeded; endometrial maturation is modified so that implantation is unlikely, and cervical mucus is thickened and sperm migration blocked.
(Notice that in this case four mechanisms are mentioned, and the prevention of implantation is listed before the prevention of conception by the thickened cervical mucus.)
The book My Body, My Health (Stewart, Guess, Stewart, Hatcher; Clinician's Edition, Wiley Medical Publications, 1979, page 169-70) states,
In a natural cycle, the uterine lining thickens under the influence of estrogen during the first part of the cycle and then matures under the influence of both progesterone and estrogen after ovulation. This development sequence is not possible during a Pill cycle because both progestin and estrogen are present throughout the cycle. Even if ovulation and conception did occur, successful implantation would be unlikely.
It was not just obscure medical journals and textbooks which contained this information in the '70s. The popular magazine Changing Times explained, "The pill may affect the movement of the fertilized egg toward the uterus or prevent it from embedding itself in the uterine lining." ("What We Know About the Pill," Changing Times, July 1977, page 21).
If most pro-lifers have been slow to catch on to this established medical knowledge (I certainly have been), many pro-choice are fully aware of it. In February 1992, writing in opposition to a Louisiana law banning abortion, Tulane Law School Professor Ruth Colker wrote,
Because nearly all birth control devices, except the diaphragm and condom, operate between the time of conception . . . and implantation . . . the statute would appear to ban most contraceptives. (The Dallas Morning News, February 6, 1992, 23A)
Colker referred to all those methods, including the Pill, which sometimes prevents implantation.
Similarly, in 1989 attorney Frank Sussman, representing Missouri Abortion Clinics, argued before the U.S. Supreme Court that "The most common forms of . . . contraception today, IUDs and low-dose birth control pills . . . act as abortifacients" (New York Times, National Edition, April 27, 1989, pages 15 & B13). (Remember, by that time all Pills were "low dose" compared to the Pill of the '60s and '70s, and 97% were low dose by recent standards, in that they had less than 50 micrograms of estrogen.)
This is such well-established knowledge that the 1982 revised edition of the Random House College Dictionary, on page 137, actually defines "Birth Control Pill" as "an oral contraceptive for women that inhibits ovulation, fertilization, or implantation of a fertilized ovum, causing temporary infertility." When the Pill successfully inhibits implantation of a fertilized ovum, it causes an abortion. (I'm not suggesting, of course, that Random House or any dictionary is an authoritative source. My point is that the knowledge of the Pill's prevention of implantation is so firmly established scientifically that it can be presented as standard information in a household reference book.)
I found on the World Wide Web a number of sources that recognize the abortive mechanism of the Pill. For instance, the "Marie Berry Archive" has an article called "Remembering to Take the Pill." It states matter-of-factly, "Combination oral contraceptives . . . inhibit two other hormones -- H and FSH -- preventing the lining of the uterus or endometrium from developing and thus not allowing ova implantation" (http://www.escape.ca/~jdk/mb0996.htm).
Another article, "Oral Contraceptives: Frequently Asked Questions," says "The combined oral contraceptive pill . . . impedes implantation of an egg into the endometrium (uterine lining) because it changes that lining" (http://www.nau.edu/~fronske/bcp.html). Again, most sources on the web are not authoritative, but these two articles, both carefully written, do reflect what is a widespread consensus about the abortive action of the Pill. (This reality does not present a problem to most of these researchers and writers, because of their belief systems.)
For years proabortionists have argued that if the Human Life Amendment, which recognizes each human life begins at conception, was to be put into law, this would lead to the banning of both the IUD and the Pill. When hearing this I used to think, "As usual, they're misrepresenting the facts and agitating people by pretending the Pill would be jeopardized by the HLA."
I realize now that while their point was to agitate people against the Human Life Amendment, they were actually correct in saying that if the amendment was passed and taken seriously, the Pill would violate it because it takes the life of an already conceived human being. They never claimed condoms or diaphragms would be made illegal by the Human Life Amendment. Why? Because when they work, those methods are 100% contraceptives -- they never cause abortions. It's because they know that the Pill sometimes prevents implantation that pro-choice advocates could honestly make the claim that an amendment stating human life begins at conception would label the Pill as a product that takes a human life.
One of the most common misconceptions about the Pill is that its success in preventing discernible pregnancy is entirely due to its success in preventing ovulation. If a sexually active and fertile woman taking the Pill does not get pregnant in 97-99% of her cycles it does not mean she didn't ovulate in 97-99% of her cycles.
Many months the same woman would not have gotten pregnant even if she wasn't using the Pill. Furthermore, if the Pill's second mechanism works, conception will be prevented despite ovulation taking place. If the second mechanism fails, then the third mechanism comes to play. While it may fail too, every time it succeeds it will contribute to the Pill's perceived contraceptive effectiveness. That is, because the child is newly conceived and tiny, and the pregnancy has just begun six days earlier, that pregnancy will not be discernible to the woman. Therefore every time it causes an abortion the Pill will be thought to have succeeded as a contraceptive. Most women will assume it has stopped them from ovulating even when it hasn't. This illusion reinforces the public's confidence in the Pill's effectiveness, with no understanding that both ovulation and conception may have in fact not been prevented at all.
In his article "Ovarian follicles during oral contraceptive cycles: their potential for ovulation," Dr. Stephen Killick says, "It is well established that newer, lower-dose regimes of combined oral contraceptive (OC) therapy do not completely suppress pituitary and ovarian function" (Fertility and Sterility, October 1989, page 580).
Dr. Thomas Hilgers, the renowned fertility expert, personally heard Dr. Ronald Chez, a scientist with the National Institute of Health (NIH), publicly state that the pills of today, with their lower estrogen doses, allow ovulation up to 50% of the time. Dr. Chez was at that time the head of the pregnancy research development branch of the NIH. (Having read this, I sought direct confirmation from Dr. Hilgers; I have a letter from him acknowledging that he did in fact hear Dr. Chez say this.)
Dr. David Sterns, in "How the Pill and the IUD Work: Gambling with Life" (American Life League, PO Box 1350, Stamford, VA 22555), states that "even the early pill formulations (which were much more likely to suppress ovulation due to their higher doses of estrogen) still allowed breakthrough ovulation to occur 1 to 3% of the time." He cites an award-winning study by Dutch gynecologist Dr. Nine Van der Vange in which she discovered in Pill-takers "proof of ovulation based on ultrasound exams and hormonal indicators occurred in about 4.7% of the cycles studied."
To check this out myself, I obtained a copy of Dr. Van der Vange's original study, called "Ovarian activity during low dose oral contraceptives," published in Contemporary Obstetrics and Gynecology, edited by G. Chamberlain (London: Butterworths, 1988). On pages 323-24, Dr. Van der Vange concludes,
These findings indicate that ovarian suppression is far from complete with the low dose OC . . . Follicular development was found in a high percentage during low-dose OC use. . . . ovarian activity is very common for the low dose OC preparations. . . . the mode of action of these OC is not only based on ovulation inhibition but other factors are involved such as cervical mucus, vaginal pH and composition of the endometrium.
This means that though a woman might not get measurably pregnant in 98% of her cycle months, there is simply no way to tell how often the Pill has actually prevented her ovulation. Given the fact that she would not get pregnant in many months even if she ovulated, and the fact that there are at least two other mechanisms that can prevent measurable pregnancy (one contraceptive and the other abortive), a 97% apparent effectiveness rate of the Pill might mean only a 70-90% effectiveness in actually preventing ovulation. (We could go much lower if we took the 50% figure stated by Dr. Chez of the National Institute of Health, but to be conservative I am choosing the higher rates of ovulation.) The other 7-27% of the Pill's "effectiveness" could be due to a combination of the normal rates of nonpregnancy, the thickening of the cervical mucus, and -- at the heart of our concern here -- the endometrium's hostility to the fertilized egg.