This will come as news to a lot of us who are pro-life. But here’s what the Times is reporting:
Labels inside every box of morning-after pills, drugs widely used to prevent pregnancy after sex, say they may work by blocking fertilized eggs from implanting in a woman’s uterus. Respected medical authorities, including the National Institutes of Health and the Mayo Clinic, have said the same thing on their Web sites.
Based on the belief that a fertilized egg is a person, some religious groups and conservative politicians say disrupting a fertilized egg’s ability to attach to the uterus is abortion, “the moral equivalent of homicide,” as Dr. Donna Harrison, who directs research for the American Association of Pro-life Obstetricians and Gynecologists, put it. Mitt Romney recently called emergency contraceptives “abortive pills.” And two former Republican presidential candidates, Newt Gingrich and Rick Santorum, have made similar statements.
But an examination by The New York Times has found that the federally approved labels and medical Web sites do not reflect what the science shows. 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charged debate over morning-after pills and abortion, a divisive issue in this election year, is probably rooted in outdated or incorrect scientific guesses about how the pills work.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.
The F.D.A. declined to discuss decisions about the effect on implantation or to say whether it would consider revising labels. But Erica Jefferson, an F.D.A. spokeswoman, acknowledged: “The emerging data on Plan B suggest that it does not inhibit implantation. Less is known about Ella. However, some data suggest it also does not inhibit implantation.”…
…Some abortion opponents said that while emergency contraceptives’ primary function may be delaying ovulation, they doubted that scientists could exclude the possibility of implantation effects.
“I would be relieved if it doesn’t have this effect,” said Richard Doerflinger, associate director of the Secretariat of Pro-Life Activities for the United States Conference of Catholic Bishops. “So far what I see is an unresolved debate and some studies on both sides,” he said, adding that because of difficulties in ethically testing the drugs on women, “it’s not only unresolved, but it may be unresolvable.”
Several scientists acknowledged that absolute proof may be elusive; in science, as James Trussell, a longtime emergency contraception researcher at Princeton, said, “You can never prove the negative.” But he and others said the evidence from multiple studies was persuasive.
UPDATE: The National Review weighs in on all this, with this analysis from an OB-GYN:
In point of fact, any drug which can act to prevent pregnancy after a woman has ovulated must have some post-fertilization effect. Whether it kills the embryo directly, or prevents the embryo from travelling down the tube, or prevents the embryo from implanting, or interferes with ovarian function, or increases immune rejection of the embryo, or directly destroys the placenta, some mechanism must be in place to interfere with the normal embryo functioning and then kill the living embryo.