One or both of these two hormones are found in many birth control products.
Implantation is necessary for the child to begin receiving nourishment from the mother.
It is really just a large dosage of combination oral birth control pills. Although the exact mechanism of this device is not well understood, the combination of chemical and device are believed to affect the sperm, egg, and endometrium. A woman cannot know in advance when any of these mechanisms will act as a contraceptive or an abortifacient. The FDA and the American College of Obstetrics and Gynecology have attempted to redefine conception to mean implantation instead of fertilization. Unlike barrier methods, spermicides, or natural methods, which prevent conception, all current birth control chemicals can be abortive.