Last month, Planned Parenthood’s Guttmacher Institute released Facts on Induced Abortions in the United States which cited a 13% decrease in abortions from 2008 through 2011. The report identified a sharp increase in medical abortions (17%), yet failed to include the incidence of abortion precipitated by emergency contraception (EC). This is due in large part to Planned Parenthood’s outright denial of the method’s abortifacient effect, stating “Use of emergency contraception pills is a way to prevent pregnancy…The pills have no effect on an established pregnancy.”
EC has the potential to act in three ways; contraceptive, intraceptive and contragestative. Several studies have proven the contraceptive nature of EC occurs most frequently by interrupting or delaying ovulation. However, these studies have failed to conclusively negate EC’s potential to act by interfering with the implantation of the embryo (intraception) or eliminating the embryo post-implantation (contragestation). For example, a 2010 study concluded “the evidence strongly supports disruption of ovulation” thus the drug is “unlikely to act by interfering with implantation although the possibility has not been completely excluded.” Another study also reported similar finding stating, “In light of the available scientific evidence and given the inherent limitations of the study, it is unlikely that emergency contraception is an abortifacient.” 
Furthermore, the specific study cited by Planned Parenthood also made similar assertions saying, “Women must know that emergency contraception pills…prevent pregnancy by delaying or inhibiting ovulation and inhibiting fertilization, but it is not scientifically possible to definitively rule out that a method may inhibit implantation of a fertilized egg in the endometrium.” The study continued, “The best available evidence is that the ability of emergency contraception to prevent pregnancy can be fully accounted for by the mechanisms that do not involve interference with post-fertilization event.” 
These studies confirm the potential of emergency contraception to act as an abortifacient agent as they cannot definitely prove the contrary. Elio Cardinal Sgreccia examined the nature of EC in his landmark book Personalist Bioethics: Foundations and Applications. His Eminence classified EC as both intraceptive and contragestative and wrote the following:
Once (emergency contraception) reaches the bloodstream, high doses of orally administered hormones can cause- if taken prior to ovulation- the prevention of ovulation in a high percentage of cases. But if ovulation occurs or the drug is administered during the post-ovulatory phase, there is a total disruption of the delicate hormonal balance usually responsible for preparing the uterine mucosa to receive the embryo that may be conceived. So it happens that if conception has occurred, the embryo is unable to implant in the endometrium, which has been significantly altered by the emergency contraception.” 
Therefore, because emergency contraception has the potential to act as a true abortifacient; it reasonable to assert the number of medical abortions detailed in the Guttmacher Institute report would be significantly higher if it were possible to verify the number of innocent lives taken via this hormonal method.
 Guttmacher Institute, “Contraception Use in the United States” (2013), found at http://www.guttmacher.org/pubs/fb_contr_use.html.
 Jeffrey D. Lewis and Dennis M. Sullivan, “Abortifacient Potential of Emergency Contraception,” Ethics and Medicine: An International Journal of Bioethics 28, no. 3 (2012), 115-116.
 James Trussel, Elizabeth G. Raymond and Kelly Cleland, “Emergency Contraception: A Last Chance to Prevent Unintended Pregnancy” (2014), 7.
 Elio Sgreccia, Personalist Bioethics: Foundations and Applications, trans. John A. Di Camillo and Michael J. Miller (Philadelphia: The National Catholic Bioethics Center, 2012), 404.