Thinking to Believe

In late September I mentioned that I would be posting on the topic of Plan B (a.k.a. the morning after bill), specifically whether it can function as an abortifacient as well as a contraceptive. Many pro-lifers have maintained that it does, including myself. More recent evidence, however, is challenging that understanding. This evidence has caused reputable pro-life apologists such as Scott Klusendorf, Greg Koukl, Melinda Penner, and Jivin Jehoshaphat to either change their minds on this issue, or at least back-off of making positive, absolutist claims that Plan B does have an abortifacient function.

Richard Poupard, an oral and maxillofacial surgeon who blogs on the Life Training Institute’s website (Scott Klusendorf’s pro-life ministry) under the name “Serge,” has written a series of posts on this topic. He presents the latest evidence on the issue from the scientific literature, all of which highly suggest Plan B does not function as an abortifacient. While I will provide links to Serge’s posts for you to read and draw your own conclusions, I would like to briefly summarize the information he presented.

While there is and will remain some doubt about the exact function of Plan B, recent studies highly suggest it does not thin the endometrium, but rather is limited to inhibiting ovulation. If you will remember from previous e-blog posts, I argued that there is good reason to believe regular oral/chemical contraceptives may have an abortifacient function because the evidence suggests they prevent the thickening of the endometrium (uterine lining), thereby producing a hostile environment for any embryo that might have been conceived when the primary function of the oral contraception (preventing ovulation) fails. A thinned endometrium reduces the chance of successful embryonic implantation, causing premature death (chemical abortion).

Since Plan B contains the same active ingredient (levonorgestrel) as many of these same oral/chemical contraceptives–albeit in a much higher dose–one would think Plan B would work in the same way; however, the evidence suggests that the increased dosage of levonorgestrel only improves the impairment of ovulation, having no effect on the endometrium. As Serge noted, “[T]here is no direct evidence that OCs [oral contraceptives] cause a ‘hostile endometrium.’ However, even if you believe that regular OCs do cause abortions, that does not indicate that Plan B EC [emergency contraception] does work via a post-fertilization event. This was a surprising aspect of this research: if Plan B acts after fertilization, the evidence…argues that it must do so by a mechanism that is different than regular OCs. … It seems that if EC works via a post-fertilization event, it must use some different mechanism than regular OCs, which appears to be based on a chronic thinning of the endometrium.”

Serge presents three lines of evidence typically employed to argue for a post-ovulatory, post-fertilization abortifacient function of Plan B:

1. It works too well to merely suppress ovulation. There must be some post-fertilization effect that reduces the number of pregnancies.
2. Since Plan B contains the same chemical ingredients as other oral contraceptives, it must work in the same way as other oral contraceptives. Since other oral contraceptives have an abortifacient function, so must Plan B.
3. Plan B has been shown to be effective even after ovulation. This can only be explained by an abortifacient function of the drug.

Serge rebuts each accordingly:

1. Recent studies reveal that Plan B is not nearly as effective as originally believed. It’s actual effectiveness makes sense if its function is limited to ovulation suppression.
2. Even if we grant the possibility that the levonorgestrel in regular OCs produces a hostile endometrium, recent studies seem to indicate that levonorgestrel has no such effect in Plan B.
3. The study purporting to demonstrate a post-ovulation effectiveness of Plan B guesstimated the date of ovulation of those involved in the study, rendering their findings inaccurate. Newer studies use more precise ways for determining ovulation, and they do not show a post-ovulation effectiveness of Plan B compared to control groups.

Serge has also written a post answering the question, “Why, if Plan B does not sometimes function as an abortifacient by thinning the endometrium, does the FDA list this as one of its functions?” In short, it is because they rely on the manufacturer’s research, and a manufacturer is required to list any possible function or side-effect of a drug (much of which is based on speculation because drug manufacturers often do not know how it is that their product works [the mechanism], only that it works [the result]). Furthermore, the data that informed the manufacturer’s report of Plan B’s effectiveness (the high effectiveness rate is the reason many have believed it must have an abortifacient as well as anti-ovulatory effect) came from clinical trials that improperly guesstimated the time of ovulation. Since experimental results are only as good as the researchers’ knowledge of when ovulation occurred in the test subjects, the results themselves are highly suspect.

Yet another post quotes Anna Glasier, a contraceptive researcher who has shown that Plan B is not as effective in conception/preventing pregnancy as once claimed. Lower rates of effectiveness argues against a post-conception abortifacient effect.

Finally, Beverly Nuckols of Life Ethics provides her own review of the latest research, echoing the conclusions of Serge. This article contains further links relating to this issue. And Philip Peters reports on two lines of evidence supporting the notion that Plan B does not produce a hostile endometrium.

Concluding Remarks

While the research cited in favor of the conclusion that Plan B has no post-ovulation/fertilization effect is strong, this is still not a shut case. Some of the same researchers point to conflicting experimental data, and admit their lack of certainty on the matter. At this point in time all that can be said is that the evidence favors the view that Plan B lacks an abortifacient function. Further research may eliminate this doubt, but until that time we should be trepid in our conclusions about Plan B. It would be premature and foolish to boldly proclaim that it has absolutely no abortifacient function, but it would be intellectually dishonest to boldly proclaim that it does have an abortifacient function. We should be trepid in our conclusions, and wise in our practices and counsel.

Personally, I think it would be wise to refrain from taking Plan B until the matter is settled. When a human life may be at stake, caution and refrain is always the wisest course of action. Additionally, I think we should advise other pro-lifers about the current state of research, and counsel them accordingly. Silence on the matter would be just as foolish as bold assertions supporting or condemning the use of Plan B. We need to be intellectually honest, wise, and tolerant of disagreement while we sort through these issues in community with other pro-lifers.