About half of all pregnancies in this country are unplanned, according to the American College of Obstetricians and Gynecologists. For a woman who wants to plan when she becomes pregnant, however, there are many choices.
Contraception -- also called birth control -- refers to methods or devices that prevent pregnancy either by preventing a woman’s egg from being fertilized by sperm or by preventing a fertilized egg from being implanted in the uterus.
Which method or methods you choose depends on several factors, including your menstrual cycle, any existing health conditions, convenience of the contraceptive and its ease of use, risk factors, side effects and cost. Your health care provider can help you determine the method that's appropriate for you.
Keep in mind that you may change your contraception method as the circumstances of your life change. When choosing a method, you should consider how often you have sex, if you are in a monogamous relationship, if you are willing to plan for sex or want a method that doesn't depend on planning, and how willing you are to track your fertile days or take a pill every day. To work effectively, a contraceptive method must be used correctly and consistently.
Below is a general description of the most common categories of contraception methods approved by the U.S. Food and Drug Administration (FDA).
These methods, available only by prescription, use hormones similar to estrogen and progestin, the hormones naturally produced by a woman’s body. The hormones prevent ovulation -- when the ovaries release an egg. Hormonal methods offer continuous contraception, but they do not protect you against sexually transmitted infections (STIs) and condoms should be used. Women who have had a stroke, have liver disease, breast cancer or problems with blood clotting should not use these methods. If you are over age 35 and smoke, your physician may advise against these methods.
Birth control pills/oral contraceptives
Combination birth control pills contain both estrogen and progestin, a synthetic form of the hormone progesterone; others have only progestin (progestin-only mini-pill). A chewable form of the combination pill is available.
Combination pills prevent ovulation. These pills are taken daily, regardless of how often a woman has intercourse. Women using the chewable tablet must drink eight ounces of liquid immediately after taking it. The usual method of taking birth control pills allows a woman to have a predictable period every four weeks. Some women may be able to use combination pills on a schedule that instead allows them to have a menstrual period every 13 weeks. This must be under the direction of a health care provider, however. The Centers for Disease Control and Prevention (CDC) says these pills are 92 to 99 percent effective when prescribed and taken correctly. Possible side effects of the combination pill include dizziness, nausea, and changes in menstruation, mood or weight. Rarely, cardiovascular disease can result; this can include high blood pressure, blood clots, heart attack and strokes. Women who smoke and are older than age 35 should not use these pills.
Progestin-only pills prevent pregnancy by thickening cervical mucus to stop the sperm from reaching the egg. The CDC says these pills are 92 to 99 percent effective when prescribed and taken correctly. They must be taken on a daily schedule, regardless of how often a woman has intercourse. Possible side effects of the progestin-only pill include irregular bleeding, weight gain and breast tenderness. Women should take these pills at the same time every day. Missing pills or taking them irregularly can lower the effectiveness of this form of birth control and increase the chances for becoming pregnant.
This is a skin patch that releases estrogen and progestin directly into the bloodstream. It is worn on the lower abdomen, buttocks or upper body, but not on the breasts. A new patch is applied once a week for three weeks. It is not worn during the fourth week to allow a menstrual period. The CDC says it is 92 percent effective, but it may be less effective in women who weigh more than 198 pounds. Patches contain more estrogen than birth control pills do. Possible side effects are similar to those of the combination oral contraceptive pill, but the risk for blood clots may be greater with the patch because it contains more estrogen. Other factors that put women at risk for blood clots are smoking, obesity, inactivity and surgery; using the patch with these risks increases them.