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Emergency Contraception Information

Preven - "Morning After Pill"

Combined oral contraceptive pills: Also known as the “morning after pill” this method involves taking birth control pills within 72 hours after intercourse. While different combinations of birth control pills have been used for emergency contraception, a brand called Preven was the first approved for use in the U.S. and Canada for emergency contraception. Each kit has an instruction booklet, a pregnancy test and 4 birth control pills that contain the hormones progestin and estrogen. Some kits also include a pill to help prevent nausea. The booklet advises women to use the pregnancy test first, because the pills will not affect an already established pregnancy. The user then takes 2 of the pills together, then 2 more 12 hours later.

How it works: The method of actions is not exactly known. According to an October 9, 1997 article in the New England Journal of Medicine:

In practice, the precise mode of action of currently available emergency contraceptive is not known, although there is evidence of effects at several critical stages of the reproductive cycle. Emergency contraception could work by inhibiting or disrupting ovulation, interfering with fertilization or transport of the zygote, or inhibiting the implantation of the embryo in the endometrium- lining of the uterus.

Failure rate: The method has an estimated failure rate of 25%. In other words, if 100 women using no contraception had intercourse one time during the second or third week of their menstrual cycle, approximately only 2 would become pregnant. Therefore, it is estimated to result in about a 75% decrease in the pregnancy rate.

Limitations:

-Needs to be taken 72 hours after unprotected intercourse

-In most states, a prescription is required

-Cannot be used with a confirmed pregnancy or undiagnosed abnormal vaginal bleeding

-Some medical practitioners may not prescribe it for women who have current migraine headaches, who smoke, or have a history of stroke or blood clots in lungs or legs.

Side effects: The most common side effects are nausea and vomiting. If vomiting occurs 2 hours or more after a dose, some recommend a repeat dose. Other side effects may include menstrual irregularities, breast tenderness, headache, abdominal cramps and dizziness.

Plan B

How it works: The method of actions is not exactly known. This method may postpone ovulation or stop fertilization. It may also prevent implantation of the embryo. Many consider this to be an abortion method because the pills may act by preventing implantation of the already fertilized egg.

Failure rate: The failure rate is about 11%

Limitations:

-Needs to be taken 72 hours after unprotected intercourse.

-In most states, a prescription is required.

-Cannot be used with a confirmed pregnancy test or undiagnosed abnormal vaginal bleeding.

Side effects: The incidence of side effects is less than with combined oral contraceptive pills. The most common side effects are nausea and vomiting. Other side effects may include menstrual irregularities, breast tenderness, headache, abdominal cramps and dizziness.

Effects on developing embryo/baby:  Little research has been done on the effects of taking progestin during pregnancy. However, it has been noted that when women who are unknowingly pregnant take oral contraceptives (levonorgestrel), there is no increased risk of genetic defects.

Source: CareNet Training Manual

*This is not an exhaustive list of all Emergency Contraceptions*