Do Emergency Contraceptive Medications Cause Early Abortions?

COMMENTARY: Part II, scientific experts give ambiguous opinions on emergency contraception’s effects.

(photo: Getty Images)

Part I of this essay can be read here.

In the first part of this essay, I outlined two conflicting opinions of conscientious Catholic thinkers on the question of whether Plan B causes early abortions. This second part summarizes the views of a secular authority on EC, James Trussell, and then sets forth my own conclusion on the issue.


The Arguments of James Trussell

Around the time that the German bishops released their statement on EC, James Trussell and Elizabeth G. Raymond published a paper entitled, “Emergency Contraception: A Last Chance to Prevent Unintended Pregnancy.” Trussell is the director of the Office of Population Research at Princeton University and is considered by some to be a world authority on the morning-after pill.

The paper does not present independent research on EC, but, rather, summarizes existing research. Addressing the mode of action of LNG, the paper cites four older studies (from 1974, 1979, 1983 and 1986) showing that LNG, used in combination with estrogen, can alter the endometrium enough to impair receptivity of an implanting embryo. But then the paper goes on to reference three subsequent studies (1994, 1996, 2000) that found no such effects on the endometrium.

The authors then question the PU-PA hypothesis, citing research that paints a mixed picture. They reference data that offers conflicting answers to the question of whether LNG administered in the pre-ovulatory phase causes alterations during the luteal phase. For example, one piece of research (from 2005) found that LNG did indeed alter the glycodelin levels in the uterus during the luteal phase. But two later studies (2007, 2010) found it did not.

The authors also reference implantation studies (referenced by Austriaco) that conclude that LNG does not impede embryos from attaching to uterine tissue in vitro. Finally, they reference three studies performed on rats and monkeys, which they say “demonstrate that levonorgestrel administered in doses that inhibit ovulation has no post-fertilization effect that impairs fertility.” But whether the results can be extrapolated to humans, they say, is “unknown.”

Much has been made of the paper’s statement:

To make an informed choice, women must know that ECPs [emergency contraceptive pills] — like all regular hormonal contraceptives such as the birth-control pill, the implant Implanon, the vaginal ring NuvaRing, the Evra patch and the injectable Depo-Provera, and even breastfeeding — prevent pregnancy primarily by delaying or inhibiting ovulation and inhibiting fertilization, but may at times inhibit implantation of a fertilized egg in the endometrium.

Some think this demonstrates Trussell’s belief that EC has an interceptive abortifacient mode of activity. But the next sentence throws this conclusion into doubt:

At the same time, however, all women should be informed that the best available evidence is that the ability of levonorgestrel and ulipristal acetate ECPs to prevent pregnancy can be fully accounted for by mechanisms that do not involve interference with post-fertilization events.

Note that the authors include Ella (ulipristal acetate) in their blanket statement that the activity of ECs can be fully accounted for by non-abortifacient events. Since Ella is a progesterone antagonist — pharmacologically, an abortion drug — Trussell’s statement seems factually tendentious. But the authors seem clearly intent in this quote on dispelling doubts about the possibility of post-fertilization abortifacient effects of LNG.


Different Conclusions: What Should Catholics Do?

We see that different conclusions result from a different reading of the scientific literature. As I said above, we are dealing with a technical question, not a moral or theological one.

Consequently, it is beyond the competency of the Church to render an authoritative judgment on it. This does not mean that Catholics, including the magisterium, cannot appeal to scientific consensus as reliable.

But — and this is important to understand — the judgment that a scientific consensus is reliable is not guarded by the Holy Spirit and therefore does not derive its credibility from the authority of Jesus, but, rather, from its own conformity with evidentiary truth.

Teaching moral principles, of course, is different. The Church rightly teaches with authority in the form: If x causes abortions, then it would be wrong to administer x. But whether x causes abortions is for scientists to answer.

What should conscientious people do? They should read the arguments for and against the judgment that LNG (Plan B) sometimes acts as an abortifacient and accept the judgment that seems to them most likely to be true. For health-care personnel involved in treating rape victims, establishing protocols for their proper care, or advising persons on the use of EC medications, familiarity with the scientific literature is especially important, all the more so in light of the recent federal court ruling that Plan B must be made available over the counter (i.e., without a prescription) for girls of all ages.

Catholic moral tradition sets forth the concept of “moral certitude” to aid us in making licit choices in the absence of perfect clarity or undebatable certitude. Moral certitude means the absence of reasonable doubts. Conscientious people therefore should ask whether there are reasonable doubts against the proposition that LNG does not sometimes act as an abortifacient. If despite arguments to the contrary, persons are left with reasonable doubts, then they should refrain from using or administering LNG.

In my own reading, I find troubling the conflicting research on the PU-PA hypothesis, lack of evidence in humans demonstrating that LNG has no serious post-fertilization effects, and ambiguity in the statements of secular authorities such as Trussell. Consequently, I am unable to reach moral certitude that LNG administered in the pre-ovulatory phase will not sometimes result in postfertilization conditions adverse enough to place the life of an embryo in jeopardy.

E. Christian Brugger writes from Denver, where he is professor

of moral theology at St. John Viannney Theological Seminary.

He is senior fellow in ethics and director of the

Fellows Program for the Culture of Life Foundation in Washington.