Emergency contraception is used after an act of unprotected sexual intercourse or after an occasion when a contraceptive method fails (for example, when a condom breaks).
Emergency contraception decreases the chance of pregnancy after one act of unprotected intercourse, including when the act occurs near the time the egg is released (ovulation)—when conception is most likely. Overall, the chance of pregnancy is about 5% after one act of unprotected sex, but closer to ovulation, it is about 20%. The sooner emergency contraception is used, the more likely it is to be effective.
Available options include
The drugs used for emergency contraception (the so-called morning-after pills) inhibit ovulation. They are more commonly used as emergency contraception than are IUDs, even though a copper IUD is the most effective form of emergency contraception.
Last full review/revision August 2013 by Laura Sech; Daniel R. Mishell, Jr., MD; Emily Silverstein