Emergency contraception, also called the "morning after pill," is used by some women when they did not use birth control during intercourse or their method of contraception failed. When taking within five days, emergency contraception prevents pregnancy for 89 percent of women, according to Planned Parenthood. While emergency contraception can help prevent an unwanted pregnancy, the method does have some drawbacks.
Limited Window of Use
Emergency contraception has a limited window of use during which it can prevent a pregnancy from occurring. While women have 120 hours after the unprotected intercourse to take it, the University of Missouri St. Louis University Health Services points out that emergency contraception works best if used within 72 hours. The longer a woman waits to use emergency contraception after unprotected intercourse, the less effective the pill.
No Protection Against Sexually Transmitted Disease
The Feminist Women's Health Center explains that emergency contraception does not protect a woman from sexually transmitted diseases such as HIV. Since emergency contraception does not have a barrier and women use it after intercourse, it cannot prevent an infection transmitted during intercourse. Other hormonal birth control methods, like the birth control pill, do not protect against sexually transmitted diseases either.
Prescription Needed
Like other hormonal birth control, emergency contraception can require women younger than 17 to get a prescription. Planned Parenthood points out that both women and men ages 17 and older do not need a prescription for emergency contraception.
Not Terminate Pregnancy
If a woman is already pregnant, emergency contraception will not work. Planned Parenthood notes that emergency contraception will not cause an abortion. Emergency contraception works by preventing the release of an egg and thickening the cervical mucus, which acts as barrier between the egg and sperm.
Restricted Use
The University of Missouri St. Louis University Health Services explains that women who cannot use birth control pills also cannot take emergency contraception. This restricted use includes women who have liver problems or unexplained vaginal bleeding, and women who are hypersensitive to the emergency contraception ingredients.
Nausea
Some women who use emergency contraception may experience nausea. Planned Parenthood points out that fewer than one in five women vomit after using emergency contraception. If a woman vomits after using emergency contraception, it can affect the pill's effectiveness if the woman's body did not fully absorb the pill.
Irregular Period
Women who use emergency contraception may have irregular periods in which their periods either come earlier or later than usual. Planned Parenthood warns that women should not use emergency contraception as their regular birth control method.
