Emergency contraception: a review of current oral options

An abortifacient is any deviceor drug that acts after implantation hasoccurred. 5 Once ablastocyst has implanted in the endometrium, it is defined as the beginning ofpregnancy. 7 EC isnot effective once implantation has taken place. Because it will not terminatean existing pregnancy, it is, therefore, not an abortifacient. According to the product labeling,women using the Preven EC kit should use the supplied pregnancy test toidentify an existing pregnancy.