Emergency contraception: a clinical review.

Emergency contraception is defined as a drug or device used to prevent pregnancy after unprotected sexual intercourse (including sexual assault) or after a recognized contraceptive failure. In the United States, 1.5 mg of levonorgestrel, packaged as Plan B, and the Copper T 380A intrauterine device are the most common emergency contraceptives available to women and are effective up to 5 days after unprotected sexual intercourse. In August 2006, Plan B was approved for over-the-counter sale to women aged 18 and older in the United States. It is not yet known whether the increased availability of emergency contraception will decrease unintended pregnancy and induced abortion rates.