Do “morning-after pills” cause abortions?

Yesterday the New York Times published a report on the alleged abortion-inducing properties of “emergency contraceptives” such as Plan B and Ella. These drugs carry FDA-mandated labels stating that in addition to delaying ovulation, they may also prevent the implantation of a fertilized egg in a woman’s uterus. That second assertion may not be supported by the latest scientific evidence, according to the NYT’s Pam Belluck:

Studies have not established that emergency contraceptive pills prevent fertilized eggs from implanting in the womb, leading scientists say. Rather, the pills delay ovulation, the release of eggs from ovaries that occurs before eggs are fertilized, and some pills also thicken cervical mucus so sperm have trouble swimming.

It turns out that the politically charged debate over morning-after pills and abortion, a divisive issue in this election year, is probably rooted in outdated or incorrect scientific guesses about how the pills work. Because they block creation of fertilized eggs, they would not meet abortion opponents’ definition of abortion-inducing drugs. In contrast, RU-486, a medication prescribed for terminating pregnancies, destroys implanted embryos.

The notion that morning-after pills prevent eggs from implanting stems from the Food and Drug Administration’s decision during the drug-approval process to mention that possibility on the label — despite lack of scientific proof, scientists say, and objections by the manufacturer of Plan B, the pill on the market the longest. Leading scientists say studies since then provide strong evidence that Plan B does not prevent implantation, and no proof that a newer type of pill, Ella, does. Some abortion opponents said they remain unconvinced.

One of those unconvinced abortion opponents is obstetrician-gynecologist Dr. Donna Harrison, who is director of research and public policy for the American Association of Pro-Life Obstetricians and Gynecologists and who was interviewed by Belluck for the NYT article. At National Review Online, Harrison describes Belluck’s piece as “a wonderful example of convolution of facts to obscure reality.”

First of all, Plan B and Ella are very different drugs with very different mechanisms of action. Plan B is a progesterone. Progesterone is a hormone that must be in a woman’s body for her to be able to allow the embryo to implant and develop the placental connections between the embryo and the mother. But Plan B is a very large dose of progesterone, higher than the woman’s body would normally make. It is the effect of that high dose which is under debate.

Ella is a second-generation derivative of the abortion drug RU-486, and is equipotent with RU-486 in blocking the action of progesterone at the level of the ovary and endometrium, one of the facts I explain in my paper on this topic. Indeed, if taken before a woman ovulates, Ella will interfere with progesterone action and prevent the egg from being released. But the critically important question is what happens when you take Ella after ovulation. And the answer is clear. Ella blocks the action of progesterone at the level of the ovary, and blocks the action of progesterone at the endometrium, both of which interfere with implantation. Ms. Belluck is in factual error in her article. The European Medical Association technical review articles state that Ella is embryocidal. That means that Ella kills embryos. I attended the FDA Advisory Committee Hearing on approval of Ella, at which data were presented which demonstrated that Ella is around 95 percent effective in preventing a clinically recognized pregnancy. One of the Advisory Committee members repeatedly pointed out to the manufacturers that there was no way the effectiveness of Ella could be explained by delaying ovulation alone. This fact does not take an FDA Advisory Committee member to figure out. If Ella works even when a woman takes it after ovulation, then of course it doesn’t work in that woman by preventing ovulation.

Regarding what, if any, affects Ella may have if taken after ovulation, the NYT reports that “the F.D.A.…and others say evidence increasingly suggests it does not derail implantation, citing, among other things, several studies in which women became pregnant when taking Ella after ovulating.” This assertion may obfuscate the reality of Ella’s abortifacient properties, says Harrison:

Ms. Belluck failed to mention is that 90 percent of those pregnancies “miscarried” and the other 10 percent were “lost to follow-up”. So what the studies supporting the FDA approval of Ella actually show is that even the dose of Ella used as “emergency contraception” is high enough to interfere with the early development of the embryo in such a fashion as to increase the miscarriage rate if a pregnancy is recognized.

The NYT article can be read here. Dr. Harrison’s response can be read here.