The Beginning of Human Life: Contraceptive Implications

Contraception by its very definition implies prevention of the formation of a conceptus. On the surface, therefore, it would seem that contraception is clearly separated from the issue of when human life begins. Nevertheless, attitudes on contraception are often influenced by attitudes toward pregnancy termination and at what stage of pregnancy the effect of a given contraceptive is exerted. In the early stages of reproduction, the events that finally result in a successfully implanted embryo are not always clear. For example, a contraceptive agent might exert its action during the early phases of fertilization but before its completion. This approach might be looked upon by some as thwarting the process and hence would raise serious concerns. For others, the whole matter is a non-issue until after fertilization is complete. For still others, implantation and not fertilization is the point at which the line is drawn. It is not always possible to separate contraceptive methods according to their mechanism of action, although, increasingly, information is available to help in such delineations.