Emergency contraception is birth control to prevent pregnancy after a woman has had unprotected sex. It acts both by preventing ovulation (the release of an egg), and also by preventing a fertilized egg from implanting in the uterus.
When can emergency contraception be used?
Emergency contraception needs to be given within 72 hours of unprotected sex. It should not be used regularly for birth control. It may be used in the following cases:
after a male condom or female condom breaks
after a rape
when no method of birth control was used
when other types of birth control fail
When a woman receives emergency contraception, she should also ask about ongoing birth control. Emergency contraception involves high-dose hormone pills or an intrauterine device, or IUD.
These methods of emergency birth control are available in the United States:
certain products that are sold specifically for emergency contraception only. These include Plan B which contains levonorgestrel.
a copper or hormone-containing IUD , which is inserted into the uterus
- oral contraceptives or birth control pills that are given in a specific way when used as emergency contraception
The birth control pills are taken in two doses. The first dose is given within 72 hours of unprotected sex. The second is taken exactly 12 hours later. The pills are most effective when they are taken within the first one to three days after unprotected sex, whereas the IUD could be inserted within the first 5 days after unprotected intercourse.
The risks of pregnancy must be weighed against the risks of emergency birth control. On one hand, short-term use of oral contraceptives does not seem to have some of the same problems as long-term use. A woman who cannot use birth control pills regularly may be able to use them safely for emergency contraception. She should talk with her health care professional for more information.
On the other hand, emergency contraception may increase the risk of ectopic pregnancy, if pregnancy occurs in spite of treatment. In an ectopic pregnancy, the egg implants outside of the uterus, usually in one of the fallopian tubes. These are the tubes that carry the egg from the ovary to the uterus. A pregnancy implanting in the tube will not survive, and may rupture, causing life-threatening bleeding.
There is also a higher risk of ectopic pregnancy with use of an IUD. In addition, IUDs can cause abdominal cramping, and sometimes may also make a small hole in the uterus.
Some of the side effects of hormones include:
Menstruation begins in almost all women within 21 days if pregnancy has been prevented. Women should have a pregnancy test and talk to a health care professional provider if a period does not start within this time frame.
In addition, the mechanisms of action of emergency contraception should be explained by the healthcare professional to a woman who is considering using EC. Women who believe life begins at conception may not be comfortable using a method of birth control that can, even infrequently, prevent an embryo from implanting in the uterus, and thus to be lost. This post-fertilization effect may occur with all forms of EC.