HOW OFTEN DOES THE PILL CAUSE ABORTION?

January 08, 2005

Why It's So Difficult to Know for Sure

How many abortions are caused by the Pill? This is difficult to determine. The answer depends on how often the Pill fails to prevent ovulation, and how often when ovulation fails and pregnancy occurs, the third mechanism prevents a fertilized egg from implanting.

Randy Alcorn posed the question to Dr. Harry Kraus, a physician and writer of popular novels with medical themes. This was his response in a December 23, 1996 email:

"How often do birth control pills prevent pregnancy by causing the lining of the uterus to be inhospitable to implantation? You will not see an answer to that question anywhere, with our present state of the science. The reason is that we can only detect early pregnancy by a hormone, beta-hcg (Human chorionic gonadotropin)which is produced by the embryo after implantation. After fertilization, implantation does not take place for approximately six days. After implantation, it takes another six days before the embryo (trophoblast) has invaded the maternal venous system so that a hormone (beta-hcg) made by the embryo can reach and be measured in the mom's blood. Therefore, the statistic you seek is not available."

Determining Breakthrough Ovulation Rates

Despite the fact that definitive numbers cannot be determined, there are certain medical evidences that provide rationale for estimating the numbers of Pill-induced abortions. Determining the rate of breakthrough ovulation in Pill-takers is one key to coming up with informed estimates.

In his Abortifacient Contraception: The Pharmaceutical Holocaust (Human Life International, 1993, page 7), Dr. Rudolph Ehmann says, "As early as 1967, at a medical conference, the representatives of a major hormone producer admitted that with OCs [oral contraceptives], ovulation with a possibility of fertilization took place in up to seven percent of cases, and that subsequent implantation of the fertilized egg would usually be prevented.

Bogomir M. Kuhar, Doctor of Pharmacy, is the president of Pharmacists for Life. In his booklet Infant Homicides Through Contraceptives (page 26), he cites studies suggesting oral contraceptives have a breakthrough ovulation rate of 2 to 10%.

World-renowned fertility specialist Dr. Thomas Hilgers estimates the breakthrough ovulation rate at 4 to 10% ("The New Abortionists," Life Advocate, March 1994, page 29).

Dr. Nine van der Vange, at the Society for the Advancement of Contraception's November 26-30, 1984 conference in Jakarta, stated that her studies indicated an ovulation rate of 4.7% for women taking the Pill. In another study, 14% of Pill-taking women experienced escape ovulation ("A Randomized Cross-over Comparison of Two Low-Dose Oral Contraceptives," H. Kuhl, et. al., Contraception, June 1985, page 583). However, this involved only twenty-two women, with three experiencing escape ovulation, so the study is too small to draw definite conclusions. In another study with a small sampling, 10% of the control group, which didn't miss a pill, experienced escape ovulation, while 28% of those missing two pills ovulated (Chowdhury and Joshi, "Escape Ovulation in Women Due to the Missing of Low Dose Combination Oral Contraceptive Pills," Contraception, September 1980, page 241- 247).

J. C. Espinoza, M.D., says, "Today it is clear that in at least 5% of the cycles of women on the combined Pill "escape ovulation" occurs. This fact means that conception is possible during those cycles, but implantation will be prevented and the "conceptus" (child) will die. That rate is statistically equivalent to one abortion every other year for all women on the Pill." (Birth Control: Why Are They Lying to Women?, page 28.)

In a segment from his Abortion Question and Answers, published online by Ohio Right to Life, Dr. Jack Willke states:

The newer low-estrogen pills allow "breakthrough" ovulation in up to 20% or more of the months used. Such a released ovum is fertilized perhaps 10% of the time. These tiny new lives which result, at our present "guesstimations," in 1% to 2% of the pill months, do not survive. The reason is that at one week of life this tiny new boy or girl cannot implant in the womb lining and dies.

There are factors that can increase the rate of breakthrough ovulation and increase the likelihood of the Pill causing an abortion. Dr. Kuhar says, The abortifacient potential of OCs is further magnified in OC users who concomitantly take certain antibiotics and anticonvulsants which decrease ovulation suppression effectiveness. It should be noted that antibiotic use among OC users is not uncommon, such women being more susceptible to bacterial, yeast and fungal infections secondary to OC use. (Contraceptives can Kill Babies, American Life League, 1994, page 1.)

When the first mechanism fails, how often does the second work?

We've seen that various sources and studies put breakthrough ovulation among Pill-takers at rates of 2-10%, 4-10%, 4.7%, 7%, 14%, 10%, and 20%. The next question is, how many times when ovulation occurs does the second mechanism, the thickened cervical mucus, prevent sperm from reaching the egg? There is no way to be sure, but while this mechanism certainly works sometimes, it may not work most of the time.

Drs. Chang and Hunt did experiments on rabbits that could not be done on human beings. ("Effects of various progestins and estrogen on the gamete transport and fertilization in the rabbit," Fertility and Sterility, 1970; 21, p. 683-686.) They gave the rabbits estrogen and progestin to mimic the Pill, then artificially inseminated them. Next, they killed the rabbits and did microscopic studies to examine how many sperm had reached the fallopian tubes and could have fertilized an egg.

Progestin, the hormone that thickens cervical mucus, might be expected to prevent nearly all the sperm from traveling to the tubes. However, it did not. In every rabbit that had taken the progestin, there were still thousands of sperm which reached the fallopian tubes, as many as 72% of the number in the control group. The progestin-caused increase in thickness of cervical mucus did not significantly inhibit sperm from reaching the egg in the rabbit.

This is certainly not definitive proof, since there can be significant physiological differences between animals and humans. However, animals are rou-tinely used for such experiments to determine possible or probable results in humans. Though I have read several studies on human sperm transport, they seemed to offer no helpful information related to this subject. Dr. Melvin Taymor of Harvard Medical School admits, "Sperm transport in women appears to be very complex" ("Some thoughts on the postcoital test," Fertility and Sterility, November 1988, page 702). The study by Chang and Hunt, while not persuasive in and of itself, at least raises questions about the extent of the contraceptive effectiveness of thickened cervical mucus.

When ovulation takes place, how often will the thickened mucus fail to prevent conception? The answer is certainly "some of the time." It may also be "much of the time," or even "most of the time."

When the second mechanism fails, how often does the third work?

The next question is, in those cases when the second mechanism doesn't work, how often does the significantly altered and less hospitable endometrium caused by the Pill interrupt the pregnancy?

The Ortho Corporation's 1991 annual report estimated 13.9 million U.S. women using oral contraceptives. Now, how often would one expect normally fertile couples of average sexual activity to conceive? Dr. Bogomir Kuhar uses a figure of 25%. This is confirmed by my research. In "Estimates of human fertility and pregnancy loss" (Fertility and Sterility, March 1996, page 503), Michael J. Zinaman and associates cite a study by Wilcox in which "following 221 couples without known impediments of fertility, [they] observed a per cycle conception rate of 25% over the first three cycles."

Multiplying this by the low 2% ovulation figure among Pill takers, and factoring in a 25% conception rate, Dr. Kuhar arrives at a figure of 834,000 birth-control-pill-induced abortions per year (Infant Homicides Through Contraceptives, page 27). Multiplying by 10%, a higher estimate of breakthrough ovulation, he states the figure of 4,170,000 abortions per year. (Using other studies, also based on total estimated number of ovulations and U.S. users, Dr. Kuhar attributes 3,825,000 annual abortions to IUDs; 1,200,000 to Depo-Provera; 2,925,000 to Norplant.)

There are several objections to this method of computation. First, it assumes all women taking the Pill, and their partners, have normal fertility rates of 25%, when in fact some women taking the Pill certainly are less fertile than this, as are some of their partners. Second, the computation fails to take into account the Pill's thickening of the cervical mucus which may significantly reduce the rate of conception. Third, it fails to consider the 3% rate of sustained pregnancy each month among Pill-takers, which obviously are not Pill-induced abortions. Of course, everything depends on the true rate of breakthrough ovulation, and the true rate of contraception due to thickened cervical mucus, both of which remain unknown. Even if the range of abortions is less than indicated by Dr. Kuhar's computation, however, the total numbers could still be very high.

Several medical researchers have assured me scientific studies could be conducted on this. So far, though, the issue of Pill-induced abortions hasn't received attention. Since no conclusive figures exist, we are left with the indirect but substantial evidence of the observably diminished capacity of the Pill-affected endometrium to sustain life. Since there is nothing to indicate otherwise, it seems possible that implantation in the inhospitable endometrium may be the exception rather than the rule. For every child who does implant, many others may not. Of course, we don't know the percentage that will implant even in a normal endometrium unaffected by the Pill. But there is every reason to believe that whatever that percentage is, the Pill significantly lowers it.

Let's try a different approach to the numbers. According to Pill manufacturers, approximately fourteen million American women take the Pill each year. At the 3% annual sustained pregnancy rate, which is firmly established statistically, in any year there will be 420,000 detected pregnancies of Pill-takers. (I say "detected" pregnancies, since pregnancies that end before implantation will never be detected but are nonetheless real.) Each one of these children has managed to be conceived despite the thickened cervical mucus. Each has managed to implant even in a "hostile" endometrium.

The question is, how many children failed to implant in that inhospitable environment who would have implanted in a nurturing environment unhindered by the Pill? The number who die might be significantly higher than the number who survive. If it was four times as high, that would be 1,680,000 annual deaths; if twice as high, 840,000 deaths. If the same number of children do not survive the inhospitable endometrium as do survive, it would be 420,000 deaths. If only half as many died as survived, this would be 210,000; if a quarter as many died as survived 105,000-still a staggering number of Pill-induced abortions each year. Perhaps the figure is even lower than the lowest of these. I certainly hope so. Unfortunately, I have seen no evidence to substantiate my hope.

Even if we believe these fatality numbers are too high, we must avoid the tendency to minimize the value of any human life. I've been told by people, "There's no way six million Jews died in the holocaust. At most it was half a million." My response is, "I think there's reason to believe the figure is much more than half a million. But suppose it was a lot less. How many deaths of the innocent does it take to qualify as a tragedy?" Similarly, we might ask, "How many children have to be killed by the Pill to make it too many?"

In his brochure How the Pill and the IUD Work: Gambling with Life" (American Life League, Stafford, VA), Dr. David Sterns asks: Just how often does the pill have to rely on this abortive "backup" mechanism? No one can tell you with certainty. Perhaps it is as seldom as 1 to 2% of the time; but perhaps it is as frequently as 50% of the time. Does it matter? The clear conclusion is that it is impossible for any woman on the pill in any given month to know exactly which mechanism is in effect. In other words, the pill always carries with it the potential to act as an abortifacient.

Perhaps the annual numbers of Pill-induced abortions add up to millions, perhaps hundreds of thousands, perhaps tens of thousands. When we factor in abortions caused by other birth control chemicals, including the Mini-Pill, Norplant and Depo-Provera, the total figures are almost certainly very high. When prolifers routinely state there are 1.5 million abortions per year in America (I have often said this myself), we are leaving out all chemical abortions and are therefore vastly understating the true number. Perhaps we are also immunizing ourselves to the reality that life really does begin at conception and we are morally accountable to act like it.

Let's make this more personal by bringing it down to an individual woman. If a fertile and sexually active woman took the Pill from puberty to menopause, she would have a potential of 390 suppressed ovulations. Eliminating those times when she wouldn't take the Pill because she wanted to have a child, or because she was already pregnant, she might have 330 potentially suppressed ovulations. If 95% of her ovulations were suppressed, this would mean she would have sixteen breakthrough ovulations.

If she is fertile and sexually active, a few of those ovulations might end up in a known pregnancy because the second and third mechanisms both fail. Of the other fourteen ova, perhaps nine would never be fertilized, some prevented by the number two mechanism, the thickened cervical mucus, and some attributable to the normal rate of nonpregnancy. And perhaps, as a result of the number three mechanism, she might have five early abortions because though conception took place, the children could not be implanted in the endometrium.

If the same woman took the Pill for only ten years, she might have one or two abortions instead of five. Again, we don't know the exact figures. Some would say these estimates are too high, but based on my research it appears equally probable they are too low.

There is no way to be certain, but a woman taking the Pill might over time have no Pill-induced abortions, or she might have one, three or a dozen of them.

We have not even taken into account here the other abortive mechanisms of the Pill documented earlier, including the peristalsis within the fallopian tube that decreases the chances of implantation, and the chemical dangers to an already conceived child whose mother unknowingly continues to take the Pill. Neither have we considered the residual effect of the Pill that can inhibit implantation as much as a few months after a woman has stopped using it.

Our beliefs should be governed by the evidence, not by wishful thinking. The numbers have not been decisively determined, and may never be this side of eternity. Based on what we do know, we must ask and answer this question: is it morally right to unnecessarily risk the lives of children by taking the Pill?

The above was taken from "Does the Birth Control Pill Cause Abortion?" a book by Randy Alcorn