Emergency contraception is a treatment "after the fact" of unprotected coitus - in the hopes that pregnancy will be prevented. There are two general methods, either (1) administration of hormones or (2) the insertion of an IUD.

In Medicine, a treatment that prevents pregnancy from becoming established is considered to be, technically, contraception. For some people in religious or other circles, the word contraception is reserved only for manuevers that are aimed to prevent fertilization. In this light, once fertilization has taken place, prevention of implantation is held as a very early abortion rather than a method of contraception. Although this is not the view of the health sciences, just how each method works will be discussed so that - best as is known, the point at which pregnancy is prevented is made clear.

As stated in a recent journal of Nursing, "patients may question the difference between the “morning after pill,” RU-486 (mifepristone/misoprostol), and emergency contraceptives. Although ECs prevent pregnancy from occurring, they are not intended to disrupt or abort an established pregnancy and pregnancy itself is a contraindication for use. RU-486, sometimes termed “the abortion pill” acts to bind progesterone receptors that sustain an early pregnancy, followed by prostaglandins that aid in expelling an established embryo."[Douglass M. Emergency contraception in the ED. [Review] [8 refs] [Journal Article. Review] Journal of Emergency Nursing. 33(2):140-2, 2007 Apr. ]

However, because insertion of a copper containing IUD in a woman with an active sexually transmitted infection has a high risk of inciting pelvic inflammatory disease, and the outcome of that can be sterility, there are women who are not good candidates for this procedure.

That includes rape victims.

Generally, hormones are taken in 2 separate rounds, and the first dose of the treatment must be taken within 72 hours to have a good chance of success.

How do these hormonal preparations prevent pregnancy? There are two types of EC pills: the progestin-only method (levonorgestrel 0.75 mg in two tablets) and the combination method (ethinyl estradiol and a progestin) (Table 1). Levonorgestrel EC works primarily by inhibiting ovulation, with some effects on sperm motility and thickening of cervical mucus [5], [6], [7]. Research indicates that the progestin-only method acts only before fertilization and has no postfertilization mechanism of action

Linda Prine, MD, quotes the Guttmacher Institute, a research group dedicated to advancing sexual and reproductive health, in estimating that if emergency contraception (EC) was widely used, the unintended pregnancy rate in the United States would decrease by half , resulting in approximately 600,000 fewer abortions per year [Prine L -Emergency contraception, myths and facts. Review. Obstet Gynecol Clin North Am - 01-MAR-2007; 34(1): 127-36, ix-x]. Whether on not the abortion rate would be influenced, it is true that the availabilty of emergency contraception is not known to many of the women who might use it. Dr.Prine speculates that: "Although EC is now available behind the counter in pharmacies to women 18 and older, younger teenagers need a prescription to obtain EC. Limited insurance coverage may continue to present a barrier to ready access, as well as pharmacist refusals to dispense EC, in many areas, and refusal by some pharmacy chains and individual pharmacies to stock the medication at all . In addition, the requirement of a government-issued identification as proof of age may pose a deterrent for women who do not have United States legal status."

The 2 existing options for EC include the Yupze regimen, which consists of 1.0 mg levonorgestrel and 0.10 mg estradiol (2 tablets) in combination, taken within 72 hours and repeated in 12 hours, or plan B, a purely synthetic progesterone formulation of 0.75 mg taken preferably within 72 hours of unprotected sex, then repeated in 12 hours.

• Women and Girls of Child-Bearing Age Who Have Been Sexually Assaulted (Rape)

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