One of the most amazing things about the stir caused by the recently leaked HHS proposal is how little, make that no, effort has been made to investigate whether the claim by the anti-abortion establishment about the mode of action of hormonal birth control is even true. A subsequent draft of the regulations without the redefinition of abortion has been released, but the underlying question — can contraception prevent implantation? — still stands.

Now, of course, for pro-choice people, this is a moot point. Even if hormonal birth control could prevent a fertilized egg from implanting in the womb, that’s not abortion because pregnancy doesn’t begin until implantation. To enter into this discussion is to first set aside the medical and legal definition of pregnancy and indulge the extremists. That’s why this discussion never really happens. But what would we find if we did indulge them?

According to the Code of Federal Regulations, The American College of Obstetricians and Gynecologists and the National Institutes of Health, pregnancy begins when a fertilized egg implants in the womb. Until it affixes to the woman’s womb a fertilized egg can not receive nutrients from the woman’s body, which is essential for it to grow. Implantation is also the only way in which a pregnancy can be determined, there is no test that can tell when an egg has been fertilized—there is no way of knowing whether or not this has happened.

Implantation is what sets in motion all the signs that pregnancy has begun. On this one point, science, medicine and the law agree: implantation is the moment at which pregnancy starts. The only dissenting group is the pro-life movement, which dismisses this definition. It, instead, would like pregnancy to start at the unknowable moment the sperm fertilizes an egg. Once sperm meets egg, any effort to prevent the egg from implanting in the womb is considered an abortion by the pro-life movement. This is one of the arguments they offer up as justification for the campaigns to keep women from using birth control. Their claim is that most birth control methods prevent fertilized eggs from implanting in the womb, which to them, though not to science, is an abortion. But even that is not true. There is no evidence that birth control methods actually do what pro-life groups claim.

Prompted, in part, by the growing efforts of anti-abortion groups to define birth control as abortion, the American Journal of Obstetrics and Gynecology in 1999 reviewed the available research on “the mechanism of action” of the contraceptive methods that so dismay pro-lifers. The authors take up the pro-life concerns directly writing, “Recently, some special interest groups have claimed, without providing any scientific rationale, that some methods of contraception may have an abortifacient effect.”

After reviewing the available literature, the authors conclude that hormonal contraceptive methods (oral contraceptives, the patch, the ring, the shot) cause a number of changes in a woman’s body which prevent
pregnancy. Primarily, what they do is simply prevent ovulation. In other words, take the pill and in almost all instances a woman won’t release an egg. No egg, no chance of pregnancy. The secondary way these contraceptives function, the authors report, is by preventing fertilization. So, on the very slim chance that a woman using a hormonal method does produce an egg another mechanism of action kicks in. Hormonal contraceptives also thicken the mucus lining of women’s reproductive organs which hamper the ability of the sperm to even get to the egg. And if a rogue sperm reaches the egg, hormonal contraceptives prevent it from penetrating the egg. Specifically, they stop the shell encasing the egg from disintegrating so a sperm can’t actually do the deed of fertilization. This is what is known about how hormonal birth control works.

What gets pro-lifers so worked up is that they insist on believing that a fertilized egg can be stopped from implanting in the womb. First off, hormonal contraceptives stop fertilization. What if, through some extraordinary, unknown, and seemingly unknowable process, an egg got fertilized? The researchers
consider the question and report , “No direct evidence exists showing that implantation is prevented by progestin-only methods” and “The evidence does not support the theory that the usual mechanism of action of IUDs is destruction of fertilized ova in the uterus,” say the authors. After reviewing all the research available on the modes of action of all contraceptives in question the authors summarize their report by explaining that “Even though the precise mechanism of action of modern contraceptive is not yet fully known, scientific evidence suggests the main mechanisms of action for each method. Inhibition of ovulation and effects on the cervical mucus are the primary mechanisms of the contraceptive action of hormonal methods. Evidence indicates that the primary mechanism of action of IUDs is the prevention of fertilization.”

“All of these methods, directly or indirectly, have effects on the endometrium [the lining of the uterus] that might prevent implantation of a fertilized ovum,” the researchers acknowledge. But as they quickly point out, “So far, no scientific evidence has been published supporting this possibility.” There’s just no evidence that any birth control method prevents a fertilized egg from attaching to the womb, even though that’s the basis for the pro-life claims.

What’s most striking about all this, is that, really, it should be a relief to pro-lifers. Birth control doesn’t have any effect on the egg once fertilized. The primary and secondary ways in which these methods work should be completely acceptable by the pro-life movement. In fact, though, they’ve taken just the opposite stance. Their argument usually sounds like this: We can’t really know for sure that in some cases, however rare, a
fertilized egg isn’t kept from fulfilling its God decreed destiny of implanting in the womb. And the dutiful scientist, limited by the research facts, must acknowledge that though there is no evidence to suggest that such a thing happens, it’s impossible to rule it out. So there! Says the pro-lifer. It can’t be ruled out. You can’t prove a negative. It’s a little bit like deriding gravity as a hypothesis. Yes, the last ten times you dropped that spoon, it crashed down on the table. But what about the eleventh time? Or the eleven  hundredth? Or the eleven millionth? There is also know way of knowing how breast feeding works as a means of birth control, which it does in the exact way hormonal methods menitioned above do, or whether fertilized eggs to breast feeding women are prevented from implanting. Applying the same exact standard here, pro-lifers would even be against the birth control method God designed. They propagate “education” campaigns, with great vehemence and assuredness, about the “abortifacient” method of birth control—all this, because while there is no evidence to show these methods actually prevent implantation of a fertilized egg, there is also no evidence to show they do not. “Insufficient evidence exists on whether cellular or biological changes in the endometrium could actually prevent implantation,” say the authors. However, their point is that it doesn’t matter. “The possibility of fertilization during combined oral contraceptive use is very small. Hence, endometrial changes are unlikely to play an important role, if any, in the observed  contraceptive effectiveness of combined oral contraceptives.” Thus pro-life campaigns against birth control are based not on scientific evidence, but rather on wishful thinking. Indeed, on a slim hypothetical chance, the pro-life movement has successfully opposed legislation that would have provided millions of women access to effective birth control methods. If the science isn’t on your side, then, the pro-life side seems to believe, ignore it.

Even some pro-life physicians, sparked by the recurring actions by the pro-life movement as a whole against birth control, stepped in to offer their medical views on the concerns their fellow pro-lifers raise. In 1998, twenty-two pro-life Ob/Gyns published an analysis entitled “Birth Control Pills: Contraceptive or Abortifacients?” and four of these pro-life physicians followed up with a more detailed paper on hormonal
contraceptives in general. The physicians open their statement boldly warning, “Currently the claim that hormonal contraceptives [birth control pills, implants (norplant), injectables (depoprovera)] include an abortifacient mechanism of action is being widely disseminated in the pro-life community. This theory is emerging with the assumed status of “scientific fact,” and is causing significant confusion among both
lay and medical pro-life people. With this confusion in the ranks comes a significant weakening of both our credibility with the general public and our effectiveness against the tide of elective abortion.” The authors explain that any effects on the uterine lining that the pro-life movement uses to support the claim that fertilized eggs are being prevented from implanting would be insignificant and has no role in the ability for a fertilized egg to implant. Fertilized eggs are able to implant in much more hostile conditions than those resulting from the mode of action from the pill. They report “The presumption that implantation of a blastocyst is thwarted by “hostile endometrium” is contradicted by the “pill pregnancies” we as physicians see. Pill company literature estimates 3 to 5 pregnancies per l00 women per year for pill users. Many of these women take the “pill” an additional month or two before finding out they are pregnant. These pregnancies generally progress with no more difficulty than non-pill pregnancies. To our knowledge, there are no studies showing that the spontaneous abortion rate in these cases is any greater than in pregnancies with a “friendly endometrium.” The pro-life physicians conclude that there is no evidence to support that the contraceptive methods in question act in the ways that would be unacceptable to the pro-life individual who
believes life begins at fertilization. They state it as plainly as they can, “the ‘hormonal contraception is abortifacient’ theory is not established scientific fact. It is speculation, and the discussion presented here suggests it is error” and continue “if a family, weighing all the factors affecting their own circumstances, decides to use this modality, we are confident that they are not using an abortifacient.”

Yet, their campaigns against birth control continue today with more intensity than even before this  intervention from the most expert on the pro-life side. Of course, arguing over inconvenient biological truths is, in many ways, besides the point when it comes to pro-life disenchantment with birth control. Don’t be
misled. This fracas is not caused by a simple scientific misunderstanding. Otherwise, they’d rush to support birth control methods that don’t ’cause abortions,’ even in their implausible view. Like the diaphragm, condom, cervical cap, and spermicides. But the pro-life forces aren’t on record anywhere in favor of methods that keep sperm and egg apart. It appears impossible to find a single instance in which a pro-life group has anything good to say about any birth control method except natural family planning—a technique most notable for its high failure rate. Remember, even the lowly condom disturbs them.