Emergency Contraception (EC) is used within 1-5 days of unprotected sex to prevent pregnancy. It can be given with or without prescription, based on health and timing factors. A variety of options are available in the United States: several types of emergency contraception pill (ECP) methods and the Cu-IUD.
Hows does EC work?
In general, EC is a very large dose of the birth control pill. It is believed that EC works by:
- Preventing the egg from being released from the ovary (Ovulation)
- Preventing the sperm from fertilizing the egg (Fertilization)
- Preventing the fertilized egg from implanting onto the lining of the uterus (Implantation)
What methods are available:
- ECPs - (Examples include Plan B or Next Choice, etc.) - ECPs consist of high doses of oral contraceptives and can be found in brand or generic forms, with prescription or over-the-counter. The best method and dosage are based on your health and circumstances. CDC suggests that this method is less effective than other methods by days 4-5 after unprotected sex.
- Ella (UPA) - Ella is an emergency contraception pill that requires a prescription from a physician. It can be taken up to 5 days after intercourse. The CDC suggests it is more effective stopping conception in days 3-5 after unprotected sex than other ECPs. This medication is a combination of large doses of oral contraceptives and misoprostol, a component of RU486.
- Cu-IUD - A copper-releasing IUD can be inserted within five days of unprotected intercourse to stop conception and can be removed when it is certain that pregnancy has not occurred.
ECPs reduce the risk of pregnancy by up to 95 percent while and an emergency IUD insertion reduces the risk by 99 percent.
Potential Side Effects
Since EC is a very large dose of the birth control pill, the risk for side effects from taking hormonal contraceptives are also increased. These side effects include but are not limited to:
- Nausea and vomitting (most common side effect)
- Cerebral hemorrhage (bleeding into the cranial cavity)
- Cerebral thrombosis (blood clot that drains blood from the brain)
- Melasma (skin discoloration; usually dark, irregular patches)
- Retinal thrombosis (blockage of the central retinal vein that carries blood away from the eye)
- Change in corneal curvature (steepening of the cornea)
- Thrombophlebitis and venous thrombosis with or without embolism (blood clots in the veins)
- Mesenteric thrombosis (blood clot in the major veins that drain blood from the intestine)
- Hemorrhagic eruption (bleeding eruption)
Refer to the Centers for Disease Control Emergency Contracepttion page for further information.