Contraceptive Measures After Unprotected Sex (cont.)
Emergency hormonal contraception
Emergency hormonal contraception is sometimes called "the morning after pill." It is actually a short course of the hormones found in oral contraceptives taken at a high dose. The exact regimen (the number of pills and the number of days) depends on the type of oral contraceptive used.
Depending upon the time during the
menstrual cycle that the emergency contraceptives are taken, these may prevent pregnancy by blocking the implantation of the fertilized egg in the uterus, by inhibiting ovulation, or by interfering with fertilization of the egg. To be considered a possible candidate for emergency contraceptive pills a woman should receive medical attention within 72 hours of unprotected intercourse. The pills are most effective when taken as soon as possible after unprotected intercourse. (In contrast, emergency contraception with an IUD may be possible 5 days after intercourse, see below.) The only known contraindication to emergency contraception is pregnancy. So a woman must not be pregnant when these methods are used. Emergency hormonal contraception may be taken on any day of the menstrual cycle.
There are no serious side effects, but the pills may cause nausea in 30% to 50% and
vomiting in 15% to 20% of women. These side effects may be controlled by taking an anti-nausea drug such as dimenhydrinate (Dramamine). Frequently a doctor will give a prescription nausea medication, such as
prochlorperazine (Compazine), at the same time as the emergency contraceptive pill. A woman may also experience breast tenderness and a temporary disruption of her menstrual cycle.
The most common type of emergency hormonal contraception involves the administration of the progesterone hormone levonorgestrel in two doses (marketed as Plan B in the U.S.). Plan B is available without prescription in the U.S. for persons 17 years of age or over. Plan B is kept behind the pharmacy counter and those who request it from the pharmacist must show proof of age. Another formulation for emergency hormonal contraception uses estrogen along with levonorgestrel, but levonorgestrel-only medication may be more effective and causes less nausea compared to estrogen-containing products.
Clinical trials using low doses of mifepristone (known earlier as RU-486, sometimes called
"the abortion pill") have shown that this agent is extremely effective as an emergency contraceptive when taken prior to ovulation, but it has not been approved for this use.
Mifepristone (Mifeprex) has been approved, in much higher doses, for terminating a pregnancy of less than 49 days' duration and must be taken under a physician's supervision.
Although effectiveness of the oral contraceptives are dependent to some extent upon how soon after unprotected intercourse they are taken, studies show that the levonorgestrel regimen (Plan B) prevented 89% of the expected number of pregnancies.
Emergency hormonal contraception has the same restrictions as the hormonal contraceptive pill. Women with a history of stroke, heart attack, liver tumor, or breast cancer need careful evaluation and counseling before taking emergency hormonal contraception. The pills do not protect women from
sexually transmitted infections
(STDs).
This strategy is not meant to be a primary birth control method. Once the emergency is over, a woman should receive proper counseling so that she can select an effective and appropriate contraceptive method to use on a regular basis if she continues to be sexually active.
Next: Emergency IUD »
- Birth Control Pills (Oral Contraceptives) - Read about the different types of birth control pills (oral contraceptives) such as monophasic, biphasic, and triphasic. Find out which birth control pill may be the best for you.
- Natural Methods of Birth Control - Natural methods of birth control are non-mechanical and non-hormonal. They are also considered fertility awareness methods and there are a variety of choices for natural birth control.
- Sexually Transmitted Diseases in Women (STDs) - Learn and become aware of common STDs in women, including descriptions, symptoms, diagnosis, and treatments of each type of infection.
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