Birth Control

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Intrauterine Device

The intrauterine device (IUD) is a small plastic device inserted into a woman’s uterus to prevent pregnancy. IUDs prevent pregnancies through a number of mechanisms: they interfere with the movement of sperm and egg, they decrease the ability of sperm to fertilize an egg, or, rarely, they prevent a fertilized egg from implanting in the lining of the uterus.

An IUD must be inserted and removed by a health-care professional. Depending on the device, it must be replaced every one to ten years. A plastic string attached to the IUD hangs down through the cervix, enabling a woman to check regularly that the IUD is properly positioned. With typical use, the IUD is about 96 percent effective in preventing pregnancy. The device may increase menstrual bleeding or cause irregular bleeding or cramping. The IUD has also been associated with an increased risk for pelvic inflammatory disease (PID), an infection of the reproductive tract. However, most cases of PID that occur in women with IUDs are attributable to an STI. Other possible problems associated with IUD use include perforation of the uterus and embedding of the IUD in the uterus. In rare cases an ectopic pregnancy occurs, a serious medical complication in which a fertilized egg implants outside of the uterus.

C

Hormonal Contraceptives

Hormonal contraceptives deliver doses of female sex hormones that alter a woman’s reproductive cycle in one or more ways. When absorbed by the body, these hormones may interfere with ovulation to prevent the maturation and release of an egg from the ovaries; thicken the cervical mucus, which interferes with sperm movement; alter the rate at which the egg moves through the fallopian tubes to prevent sperm from meeting the egg; or change the condition of the uterine lining to prevent fertilized eggs from implanting in it.

Available only by prescription, hormonal contraceptives are extremely effective in preventing pregnancy when used properly. Many people prefer them because their use does not interfere with sexual spontaneity. Among the drawbacks are reduced effectiveness when used in conjunction with some medications and lack of protection against STIs. Hormonal contraceptives may be administered by pill form, implant, injection, or through vaginal rings or skin patches.

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C

1

Birth Control Pill

The birth control pill, or oral contraceptive, was first approved for use in the United States in 1960. These early pills contained high doses of female sex hormones that have since been found to cause long-term health problems, such as blood clotting. The birth control pills available today have much lower doses of hormones. The most common type of birth control pill is the combination pill, which contains low doses of both estrogen and progestin (a synthetic form of progesterone). Another type of birth control pill contains only progestin.

To prevent pregnancy a woman takes one birth control pill each day for 21 days, after which she takes no pill or a placebo (a pill containing no active ingredients) for 7 days. With typical use, the pill is 95 percent effective in preventing pregnancy.

In addition to its effectiveness as a birth control method, the pill can relieve menstrual pain and reduce menstrual bleeding. It may also offer some protection against PID, endometrial and ovarian cancer, endometriosis (growth of uterine tissue outside the uterus), and uterine fibroid tumors (benign growths). Adverse side effects can include breakthrough bleeding (bleeding between periods), headache, hypertension, weight gain, mood change, decreased sexual desire, blood clotting disorders, cardiac complications, breast tenderness, and galactorrhea (discharge of milk from the breast).

C

2

Hormonal Implant

With typical use, hormonal implants are the most highly effective form of birth control except for continuous abstinence and surgical sterilization. A health-care professional implants a matchstick-sized tube filled with a synthetic progesterone-like hormone called etonogestrel (progestin) just under the skin of a woman’s upper arm. The implants can remain in place up to three years. Adverse side effects include irregular intervals between menstrual periods, breakthrough bleeding, headache, acne, weight gain or loss, depression, breast tenderness, and infection or skin discoloration at the implant insertion point. The only long-term hormonal implant approved for use in the United States is sold under the brand name Implanon.

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3

Contraceptive Injection

Contraceptive injections contain synthetic hormones that a health-care professional injects into the muscles of a woman’s buttocks or arm. This form of birth control requires regular visits to a clinic so that a health-care professional can administer the injection. With typical use, contraceptive injections are about 99 percent effective in preventing pregnancy.

There are two types of contraceptive injections: Depo-Provera and Lunelle. Depo-Provera contains the synthetic hormone progestin and protects against pregnancy for 12 weeks. Lunelle contains a combination of estrogen and progestin and must be injected once a month. The most common side effect of contraceptive injections is irregular bleeding. For most women periods become lighter and less frequent, and they may stop altogether. Some women may develop heavier and longer periods. Other adverse side effects include breakthrough bleeding, weight gain, headache, sore breasts, depression, nausea, vaginal dryness, and acne.

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