Emergency contraception

After taking emergency contraception, a woman's next menstrual cycle may start earlier or later than expected and the menstrual flow may be lighter or heavier than usual. Still, most women will start their next period within 7 days of the expected date. If a woman's menstrual bleeding does not start within 3 weeks after taking emergency contraception, she might be pregnant and should call or visit her health care provider.

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Emergency contraception drugs do not appear to harm an early pregnancy. However, women who believe that they are already pregnant and may have been for longer than several days should not take such drugs, since their effects have not been well studied. Also, women who have vaginal bleeding for an unknown reason should discuss this with their health care provider before taking emergency contraception.

Women who cannot take birth control pills regularly in most cases may still be able to use emergency contraceptives, but they should also discuss this option with their health care provider.

IUD placement has risks of pelvic infection and uterine injury, although these are quite rare. Long-term use of an IUD for birth control may cause side effects such as heavy menstrual bleeding and painful menstrual cramps.

Women who are interested in IUD placement for emergency contraception should discuss the risks and benefits of IUD use with their health care providers.

SPECIAL CONSIDERATIONS:

Some people have confused emergency contraception drugs with the "abortion pill," but they are not the same thing. A woman who knows she is pregnant takes the "abortion pill" with the intent to terminate the early pregnancy (usually 4 to 7 weeks after conception). Emergency contraception pills are taken after unprotected sex to prevent conception from occurring.

However, if emergency contraception is taken after the sperm and egg have already joined (but before the fertilized egg has implanted in the uterine wall), pregnancy may still be prevented by inhibition of transport through the tubes or implantation in the uterus. So, sometimes emergency contraception prevents fertilization, and sometimes it prevents implantation after fertilization has already occurred. However, emergency contraception will not end an early pregnancy that has already implanted in the uterus.

If emergency contraception fails and the woman becomes pregnant, there do not appear to be any long-term effects on the pregnancy or the fetus.

Emergency contraception provides a second chance at preventing undesired pregnancies, but it should not be used as a routine birth control method, because it is actually less effective at preventing pregnancies than most types of birth control. Unprotected intercourse also puts a woman at risk of sexually transmitted infections such as HIV, and emergency contraception does not protect against infections. Health care providers can provide counseling and possibly treatment if this is a concern.

There is a "morning-after" medication combination for women or men who have been raped or who believe they may have been exposed to HIV infection through unprotected sex or needle-sharing -- but this is a much more involved course of drugs that can have serious side effects and may not always prevent infection. If you think you have been exposed to HIV, contact an emergency room or knowledgeable HIV specialist or organization and ask about "postexposure prophylaxis" immediately.