The Religious Consultation
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Chicago Tribune , June 20, 2005 Morning-after
pill's not abortion, scientists say Amid a heated national debate over emergency contraception, some scientists are marshaling evidence to challenge the belief that the "morning-after pill" is equivalent to abortion. Abortion opponents object to the pills, saying they work by preventing implantation of a fertilized egg in the womb and thus destroy an early embryo. Some pharmacists are refusing on moral grounds to dispense emergency contraception. But the scientists say there is no scientific evidence the pills prevent implantation--and considerable evidence they work mainly by blocking the release of an egg from the woman's ovary, so no embryo is formed. "The pervasive myth out there is that emergency contraception is an abortifacient," said Dr. David Archer, director of clinical research at the Contraceptive Research and Development Program of Eastern Virginia Medical School in Norfolk. "But there's no evidence scientifically that that's true." For one thing, Archer points out, emergency contraception generally doesn't work if taken after a woman has ovulated. On the other hand, no one can prove that the pill doesn't interfere with implantation. Whether emergency contraception, known as Plan B, works before or after fertilization is a crucial question only for those who believe life begins when sperm meets egg. The medical establishment--including the National Institutes of Health, the U.S. Food and Drug Administration and the American College of Obstetricians and Gynecologists--holds that emergency contraceptives prevent pregnancy. Abortifacients such as RU-486 terminate pregnancies. But that distinction assumes pregnancy begins with the implantation of a fertilized egg in the uterine lining. Anti-abortion forces believe a woman is pregnant from the moment an egg is fertilized and interfering with the development of a fertilized egg is the same as killing a baby. The conservative Family Research Council, for example, says the "principal function" of the morning-after pill "is an anti-implantation, or abortion, effect." The latest round in the national debate over the pills started with reports that some pharmacists were refusing to dispense them. In Missouri, a recent survey of 920 pharmacies found that 70 percent do not stock Plan B and most won't order it if a customer requests it. In April, Gov. Rod Blagojevich ordered Illinois pharmacies to fill prescriptions for Plan B without delay, an order that was promptly challenged in court. Earlier this month the Catholic Conference of Illinois joined the fray, telling state regulators that pharmacists should not be required to choose between their conscience and their livelihood. Surprisingly little is known for sure about the action mechanism of the pills, which contain an elevated dose of the hormone used in some regular birth control pills and are meant to be taken within 72 hours of unprotected sex. The package insert for Plan B says that while the pill works principally by stopping ovulation (release of an egg) or fertilization, it may also prevent implantation of a fertilized egg by altering the lining of the uterus. But experts say that information comes from studies on regular daily use of birth control pills, and not from research on Plan B, which is taken on a one-time basis. Last July, a review of the scientific literature by experts at the Karolinska Institute in Stockholm concluded that the contraceptive effects of a one-time dose of levonorgestrel, the active ingredient in Plan B, "involve either blockade or delay of ovulation ... rather than inhibition of implantation." Then, in December, Horacio Croxatto of the Chilean Institute for Reproductive Medicine reported that emergency doses of levonorgestrel interfered with ovulation 82 percent of the time in women who took it. Blood tests on those women showed that the drug suppressed the monthly surge of luteinizing hormone, which triggers ovulation. "We can't prove it," said Archer, "but a lot of inferences are strongly supportive that emergency contraception does not work after fertilization. ... Once [an egg is] fertilized, there's not an iota of evidence that says that fertilization won't go forward." Archer, a gynecologist and reproductive endocrinologist, also noted that emergency contraception generally doesn't work if it's given after ovulation, around the 14th day of the woman's menstrual cycle. Anti-abortion doctors and lay activists argue that the Plan B pill doesn't always block ovulation, which would allow fertilization to take place. In such cases, they say, the pill would abort the early embryo--probably by causing changes in the uterine lining. Experts concede there is no way to rule out the possibility that emergency contraceptives--or any other type of birth control pills--may sometimes work after fertilization. There's no way to determine when fertilization has taken place inside the body. "It would be misleading to say emergency contraception can never work after fertilization," said James Trussell, director of the Office of Population Research at Princeton University. But to Dr. Don M. Henry, an obstetrician and gynecologist in Munster, Ind., who has had patients encounter trouble obtaining emergency contraception, that way of thinking doesn't make sense. "You can't prove a negative," said Henry. "You can't prove coffee doesn't disrupt implantation." Many opponents of emergency contraception say they do not have the same objection to standard birth control pills. State Rep. Ron Stephens (R-Greenville), a pharmacist, falls into that category. He dispenses regular birth control pills but not emergency contraception, saying it's because the latter prevents implantation of a fertilized egg. "One you take to prevent pregnancy," he said. "The other you take to end a pregnancy." Archer and other researchers say taking that position is illogical, because regular birth control pills have been shown to cause changes in the lining of the uterus. Scientists believe that in cases when birth control pills fail to stop ovulation, those changes in the uterus could provide a backup mechanism by blocking implantation. But in their review of the studies on emergency contraception, the Karolinska researchers found that one-time treatment with levonorgestrel had no effect on the uterine lining. Some doctors opposed to Plan B on moral grounds now concede that it appears to work primarily by stopping ovulation. One of them is Dr. W. David Hager, a Bush appointee to an FDA advisory council who played a role last year in blocking the approval of Plan B for over-the-counter sales. Hager said his opposition stemmed from concerns about its health effects on young women and girls, not about any potential to harm embryos. "My feeling is that the principal method of action is to prevent ovulation," said Hager, an abortion foe and professor of gynecology and obstetrics at the University of Kentucky. But Hager said it's still possible that Plan B sometimes prevents an embryo from gaining a foothold. Trussell said he supports doctors who say women need to know it's possible that emergency contraception may affect embryo implantation. But that's true for nearly all methods of contraception, he added--including breast-feeding. Breast-feeding, which can have a contraceptive effect up to six months after the birth of a child, also causes changes in the uterine lining. In that respect, it carries the same possibility of interfering with implantation. "If you're talking about informed consent," said Trussell, "then it's not right to withhold evidence that breast-feeding may work in the same way." jperes@tribune.com
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