The Food & Drug Administration quietly changed its consumer guide to birth control (PDF) this week, deleting claims that two kinds of contraceptives—the morning-after pill and the copper IUD—can prohibit an egg from implanting in the womb after fertilization.
The changes are significant because a number of religious groups, pro-lifers, and conservative politicians view contraceptives that prevent implantation as the equivalent of an abortion since the egg has already been fertilized.
The changes follow a New York Times story last week questioning claims by the FDA and other medical institutions that the morning-after pill, which is taken after sex, prohibits implantation. “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charged debate over morning-after pills and abortion, a divisive issue in this election year, is probably rooted in outdated or incorrect scientific guesses about how the pills work,” wrote Times reporter Pam Belluck.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.”