Birth Control

Today, women and men can choose birth control (or contraception) methods that fit their lifestyles and preferences. For married couples and people in long-term relationships, the decision of when and what kind of birth control to use is one that is best made together. The effectiveness of a birth control method is measured in terms of the number of pregnancies that can be expected if 100 couples used the method for 1 year. For example, a 2-percent failure rate means that of those 100 couples, two women could expect to become pregnant during the year while using that method. Without using any birth control, 85 of the 100 couples could be expected to conceive within the year.

Birth Control Methods

 There are many ways to help you control when or if you want to have children. Birth control options range from natural means, such as the rhythm method, to surgical sterilization. Not all birth control methods offer protection against sexually transmitted diseases (STDs). Condoms, when used correctly, provide the best protection against STDs. Using a spermacide with a condom may provide additional protection against some STDs.

Natural Methods

Natural methods (20-percent failure rate) don’t use devices, pills, or other products. There are two kinds of natural birth control methods:

• To practice the rhythm method, a couple abstains from having sexual intercourse during the time a woman is ovulating (the time in the menstrual cycle when an egg is ready to be fertilized). The couple can calculate this time by counting the days during the woman’s menstrual cycle (calendar method), checking for changes in vaginal mucus (ovulation method), or checking for changes in body temperature and vaginal mucus (symptothermal method). There are kits available that can help determine a woman’s fertile period.

•  Using the withdrawal method, the man pulls his penis from the woman’s vagina before he ejaculates. This requires a great deal of control on the man’s part. And even with control, sometimes sperm may be expelled before ejaculation. The failure rate of this method is very high.

Spermicides

Spermicides (18-percent failure rate) kill sperm before they can enter the uterus and fertilize the egg. They come in foams, jellies, suppositories, creams, and foaming tablets. Spermicides are inserted in the vagina before intercourse, giving protection for up to 2 hours. When used with condoms or diaphragms, spermicides give added protection against pregnancy and even some sexually transmitted diseases. Occasionally a man or woman may be allergic to spermicides.

Barrier Methods

Barrier methods (12- to 18-percent failure rate) block sperm from reaching the egg. Some, such as condoms and contraceptive sponges, can be bought over the counter and are not expensive. A diaphragm or a cervical cap must be fitted by a doctor.

• A condom is put on over the erect penis. When the man ejaculates, the fluid is collected at the end of the condom. Condoms can fail if they break or if the penis gets soft while still in the vagina and the condom slips off. When using a condom, the man should withdraw immediately after ejaculation. Condoms have a failure rate of 12 percent.

• A diaphragm is a saucer-shaped piece of rubber with a flexible metal rim. It is inserted in the vagina and then sits snugly against the cervix, or entrance to the uterus. Although the diaphragm is a partial physical barrier against sperm, the real protection comes from the spermicidal cream or jelly it holds against the cervix. A diaphragm must be left in place for 6 hours after intercourse. The diaphragm has a failure rate of 12 percent. A cervical cap is smaller than a diaphragm. It provides an airtight seal over the cervix. It requires less spermicide to be effective. The cervical cap must be left in place for at least 6 hours after intercourse, but it can be left in the vagina for up to 72 hours. It has a failure rate similar to that of the diaphragm.

Intrauterine Devices

Intrauterine devices ( IUDs; 2-percent failure rate) are small devices placed inside the uterus (see illustration). They may be made of plastic and may contain copper or hormones. They are thought to keep fertilized eggs from implanting in the uterine lining, although why they prevent conception is not fully known. The copper ParaGard IUD also kills sperm as they approach the IUD, preventing fertilization. A copper IUD can be worn for up to 10 years. IUDs with hormones must be replaced every year. The IUD is easier to insert and less likely to be expelled accidentally in women who have already had at least one child. In some women an IUD can cause bleeding between periods or difficult periods. A woman with an IUD is shown how to check to make sure it is still in place. Occasionally an IUD is expelled by the body.

Birth Control Pills

Birth control pills (1- to 3-percent failure rate) prevent ovulation and change cervical mucus and the lining of the uterus. Birth control pills, which are only available by prescription, contain synthetic versions of the female hormones estrogen and progesterone or just progesterone. There are different formulations of pills available, so if you have side effects with one kind of birth control pill, your doctor can try another. The pill is convenient and highly effective when taken every day. Progesterone-only pills fail 3 percent of the time; combination progesteroneestrogen pills fail only 1 percent of the time. The pill has some risk of heart disease for women who are older than 35 and who smoke heavily.

Progestin Injections

Injections of progestin, the synthetic form of the female hormone progesterone (less than 1-percent failure rate), prevent ovulation and prevent implantation of any fertilized egg by keeping the lining of the uterus from building up. The Depo-Provera injection is given every 3 months. Proper timing of injections is important to provide full protection from pregnancy. When the first injection is given within the first 5 days of a normal menstrual cycle, protection from pregnancy is immediate. Infrequent or irregular periods are a common side effect. Depo-Provera can reduce bone mass, increasing osteoporosis risk.

Birth Control Patch

The birth control patch (1-percent failure rate) is a thin beige square that sticks to the skin like an adhesive bandage. It delivers hormones through the skin into the bloodstream. Once a week, a new patch is applied to the buttocks, abdomen, upper torso (but not to the breasts), or the outside of the upper arm. Cigarette smoking increases the risk of cardiovascular side effects with this method, especially in women over age 35.

Vaginal Contraceptive Ring

The vaginal contraceptive ring (1-percent failure rate) is a soft, flexible plastic ring about two inches in diameter. Once a month, a new ring is inserted into the vagina, where it slowly releases estrogen and progestin hormones. Women who smoke have an increased risk of cardiovascular side effects, especially if they are over age 35.

Emergency Contraception

Emergency contraception is available when a woman has sex without using birth control or when a birth control method fails, such as a condom breaking. Generally, emergency contraception is done by giving high doses of birth control pills within 3 days of the unprotected sexual intercourse. This is not something a woman should do on her own, however; if you have had unprotected sex and are concerned about pregnancy, talk to your doctor about emergency options.

Surgical Sterilization

Surgical sterilization permanently blocks sperm from connecting with the egg. Either the sperm are blocked from leaving a man’s body or the route to the egg in the woman’s body is closed. It is permanent birth control, and should be done only when a man or woman is sure that he or she no longer wants to be able to have children.

• In women, tubal ligation closes the fallopian tubes. It is done under a general anesthetic and the fallopian tubes are tied, cut, banded, or sealed.

• In men, a vasectomy closes the tubes that carry sperm to the penis. It is usually done in a doctor’s office, under a local anesthetic.