The most recent scientific study on Levonorgestrel, the essential component of the “morning-after pill” or “emergency contraceptive,” confirms that the drug does indeed have a third effect on users, which consists in preventing the implantation of a fertilized ovum in the womb of the mother.
The promoters of the drug in Latin America, where most countries have laws against abortion, have argued that the there is no scientific basis for the “third effect,” and that therefore the drug should be legalized. Dr. Horacio Croxatto, professor at the Chilean Institute of Reproductive Medicine, said in 2006 that the morning-after pill “is not abortifacient because it only prevents pregnancy by stopping ovulation.”
Nevertheless, the most recent study (2007) by Doctors Mikolajczyk and Stanford of the Department of Medicine in Public Health of the University of Bielefeld (Germany) clearly indicates that the pill’s “real effect” includes mechanisms that prevent implantation.
Published by the magazine Fertility and Sterility, the study used data from multiple clinical studies with advanced mathematical models and concluded that if emergency contraception only inhibited ovulation its true effectiveness would only be in a range of 8-49 percent. If it acted before ovulation and if it inhibited ovulation completely, its true effectiveness would be between 16-90 percent. The rest of the pill’s effectiveness consists in its anti-implantation mechanisms, which cause an abortion.