It’s remarkable: There was an 11 percent decline in the number of abortions in the United States between 1994 and 2000. Birth rates fell steadily during the 1990s as well. Much of this decline is because of improvements in birth control methods and use.

Emergency contraceptive pills account for up to 43 percent of the decline in abortions. An Alan Guttmacher Institute study estimates that in 2000 alone, emergency contraception prevented 51,000 pregnancies that would have ended in abortions.

If every woman in America knew about and had easy access to birth control and emergency contraception, the number of abortions would drop even lower.

A reality of life is this: Men and women have unprotected sex and women are at risk of pregnancy as a result. This can happen for many reasons. Couples may neglect to use a condom; maybe because they are too embarrassed to talk about it, maybe they are too intoxicated to remember. Even if one is used, a condom can break if not used correctly or if it is defective. Women may forget to take their birth control pills. Teen-agers tend to be in denial about the fact that they can get pregnant, and don’t take precautions. Women are sexually assaulted.

In situations like these, fears of pregnancy may arise the morning after. This is where emergency contraception comes in. It used to be called “the morning-after pill,” but this is an inaccurate term, since emergency contraception pill is effective if taken any time within three days after unprotected intercourse. (A World Health Organization study found that it could be used up to five days later, but with diminishing effectiveness.)

Emergency contraception comes in several forms. Traditionally, higher-than-usual doses of regular birth control pills were used. Then, in the mid-1990s, Preven© was developed, which contains the same hormones as birth control pills (progestin and estrogen), specially packaged for use as emergency contraception.

The newest brand of emergency contraception is called Plan B©. It contains progestin only and so has fewer estrogen-related side effects, such as nausea and vomiting. If taken within 24 hours of unprotected intercourse, it prevents 95 percent of pregnancies. If taken within 72 hours, it can prevent 89 percent of pregnancies.

Whichever type is used, the directions for taking emergency contraception pills are the same: The first dose is taken as soon as possible after unprotected intercourse and the second dose is taken 12 hours later. The sooner the pills are taken after intercourse, the more effective they are.

Emergency contraception works in one or more ways, depending on the point in a women’s menstrual cycle that it is taken. The hormones:

inhibit or delay the release of an egg from the ovary (ovulation).

block sperm from fertilizing an egg.

prevent the implantation of a fertilized egg by altering the endometrial lining of the uterus.

Side effects such as nausea and vomiting are most common. Fatigue, headache, dizziness and breast tenderness can also occur, but these normally go away within one day after taking the pills. The next menstrual period may come a few days early or late.

Emergency contraception can be obtained from your county health department, and from most primary care providers and OB/GYNs. Prescriptions are also available from Internet companies such as www.getthepill.com and www.themorningafterpill.net. In Washington state, pharmacies can dispense emergency contraception pills directly; call ahead to be sure an authorized pharmacist is available.

Kathryn B. Brown is a family nurse practitioner with a master’s degree in nursing from OHSU. Is there a health topic you would like to read about? Send your idea to kbbrown@eastoregonian.com.