Contraception (birth control) prevents pregnancy by interfering with the normal process of ovulation, fertilization, and implantation. There are different kinds of birth control that act at different points in the process.
Every month a woman's body begins the process that can potentially lead to pregnancy. An egg (ovum) matures, the mucus that is secreted by the cervix (a cylindrical-shaped organ at the lower end of the uterus) changes to be more inviting to sperm, and the lining of the uterus grows in preparation for receiving a fertilized egg. Any woman who wants to prevent pregnancy must use a reliable form of birth control. Birth control (contraception) is designed to interfere with the normal process and prevent the pregnancy that could result. There are different kinds of birth control that act at different points in the process, from ovulation through fertilization to implantation. Each method has its own side effects and risks. Some methods are more reliable than others.
Although there are many different types of birth control, they can be divided into a few groups based on how they work. These groups include:
- Hormonal methods: These use medications (hormones) to prevent ovulation. Hormonal methods include birth control pills ( oral contraceptives ), Depo Provera injections, and Norplant.
- Barrier methods: These methods work by preventing the sperm from getting to and fertilizing the egg. Barrier methods include male condom and female condom, diaphragm, and cervical cap. The condom is the only form of birth control that also protects against sexually transmitted diseases , including human immunodeficiency virus (HIV) that causes acquired immune deficiency syndrome (AIDS).
- Spermicides: These medications kill sperm on contact. Most spermicides contain nonoxynyl-9. Spermicides come in many different forms such as jelly, foam, tablets, and even a transparent film. All are placed in the vagina. Spermicides work best when they are used at the same time as a barrier method.
- Intrauterine devices (IUDs): These devices are inserted into the uterus, where they stay from one to ten years. An IUD prevents the fertilized egg from implanting in the lining of the uterus and may have other effects as well.
- Tubal ligation: This medical procedure is a permanent form of contraception for women. Each fallopian tube is either tied or burned closed. The sperm cannot reach the egg, and the egg cannot travel to the uterus.
- Vasectomy: This medical procedure is a the male form of sterilization and should be considered permanent. In vasectomy, the vas defrens, the tiny tubes that carry the sperm into the semen, are cut and tied off.
Unfortunately, there is no perfect form of birth control. Only abstinence (not having sexual intercourse) protects against unwanted pregnancy with 100 percent reliability. The failure rates, or the rates at which pregnancy occurs, for most forms of birth control are quite low. However, some forms of birth control are more difficult or inconvenient to use than others. In actual practice, the birth control methods that are more difficult or inconvenient have much higher failure rates, because they are not used faithfully.
All forms of birth control have one feature in common. They are only effective if used faithfully. Birth control pills work only if taken every day; the diaphragm is effective only if used during every episode of sexual intercourse. The same is true for condoms and the cervical cap. Some methods are automatically working every day, no matter what. These methods include Depo Provera, Norplant, the IUD, and tubal sterilization.
There are many different ways to use birth control. They can be divided into several groups:
- By mouth (oral): Birth control pills must be taken by mouth every day.
- Injected: Depo Provera is a hormonal medication that is given by injection every three months.
- Implanted: Norplant is a long-acting hormonal form of birth control that is implanted under the skin of the upper arm.
- Vaginal: Spermicides and barrier methods work in the vagina.
- Intra-uterine: The IUD is inserted into the uterus.
- Surgical: Tubal sterilization is a form of surgery. A doctor must perform the procedure in a hospital or surgical clinic. Many women need general anesthesia.
The methods of birth control differ from each other regarding when they are used. Some methods of birth control must be used specifically at the time of sexual intercourse (condoms, diaphragm, cervical cap, spermicides). All other methods of birth control must be working all the time to provide protection (hormonal methods, IUDs, tubal sterilization).
Condoms and spermicides
Condoms are about 85 percent effective in preventing pregnancies. That means that out of 100 females whose partners use condoms, 15 will still become pregnant during the first year of use, according to the nonprofit advocacy group Planned Parenthood. Unwanted pregnancies usually occur because the condom is not attached or used properly or breaks during intercourse. More protection against pregnancy is possible if a spermicide is used along with a condom. Spermicide is a pharmaceutical substance used to kill sperm, especially in conjunction with a birth-control device such as a condom or diaphragm. Spermicides come in foam, cream, gel, suppository, or as a thin film. The most common spermicide is called nonoxynol-9, and many condoms come with it already applied as a lubricant. However, spermicides do not kill HIV or other sexually transmitted viruses and do not prevent the spread of HIV and other STDs. Also, nonoxynol-9 can irritate vaginal tissue and thus increase the risk of getting an STD. In anal sex, especially between two males, spermicides also can irritate the rectum, increasing the risk of getting HIV. Spermicides are specifically discouraged for use by gay or bisexual males for anal sex.
Latex condoms are also recommended over condoms made from other materials, especially lambskin, because they are thicker and stronger and have less risk of breakage during sex. Non-latex condoms do not prevent the spread of STDs, including HIV, and should not be used by gay or bisexual men or men who have HIV or other sexually transmitted diseases. Condoms are available over-the-counter, meaning they do not require a prescription, and there are no age restrictions on purchasing condoms. They are available at a variety of locations, including drug stores, convenience stores, supermarkets, and family planning clinics. They are also available for purchase on the Internet.
FEMALE CONDOM The female condom is a seven-inch polyurethane pouch that fits into the vagina. It collects semen before, during, and after ejaculation, keeping semen from entering the uterus through the cervix and thus protecting against pregnancy. In one year of use, it is 79 percent effective in preventing pregnancies. It also reduces the risk of many STDs, including HIV. There is a flexible ring at the closed end of the thin, soft pouch of the female condom. A slightly larger ring is at the open end. The ring at the closed end holds the condom in place in the vagina. The ring at the open end rests outside the vagina. When the condom is in place during sexual intercourse, there is no contact of the vagina and cervix with the skin of the penis or with secretions from the penis. It can be inserted up to eight hours before sex.
There are risks associated with some forms of birth control. Some of the risks of each method are:
- Birth control pills: The hormone (estrogen) in birth control pills can increase the risk of heart attack in women over forty who smoke.
IUD: This device can increase the risk of serious pelvic infection. The
IUD can also injure the uterus by poking into or through the uterine
wall. Surgery might be needed to fix this injury.
- Tubal sterilization: "Tying the tubes" is a surgical procedure and has all the risks of any other surgery, including the risks of anesthesia, infection, and bleeding.
- Condom: The most common problems associated with condoms are breakage during use and improper technique in using condoms. These can lead to pregnancy and sexually transmitted diseases, especially HIV.
No specific preparation is needed before using contraception. However, a woman must be sure that she is not already pregnant before using a hormonal method or having an IUD placed.
Many methods of birth control have side effects. Knowing the side effects can help a woman to determine which method of birth control is right for her. There is no perfect form of birth control. Every method has a small failure rate and side effects. Some methods carry additional risks. However, every method of birth control has fewer risks than pregnancy. The risks include:
- Hormonal methods: The hormones in birth control pills, Depo Provera, and Norplant can cause changes in menstrual periods, changes in mood, weight gain, acne , and headaches. In addition, once a woman stops using Depo Provera or Norplant, she may go many months before she begins ovulating again.
- Barrier methods: A woman must insert the diaphragm in just the right way to be sure that it works properly. Some women get more urinary tract infections if they use a diaphragm because the diaphragm can press against the urethra, the tube that connects the bladder to the outside.
|Type of contraceptive||Description||Use||Failure rate per 100 women in one year|
|SOURCE : Food and Drug Administration, December 2003; Planned Parenthood, March 2004; kidshealth.org, September 2001.|
|Abstinence||Refraining from intercourse, anal sex, and oral sex||Universally applicable. Also prevents spread of sexually transmitted diseases||0|
|Birth control pill||Prescription pill containing estrogen and progestin that suppresses ovulation||Must be taken daily, regardless of the frequency of intercourse||1-2|
|Cervical cap with spermicide||Soft rubber cup that fits around the cervix, obtained by prescription||Inserted before intercourse. May be difficult to insert||17-23, depending on type|
|Condom, female||Lubricated sheath that is inserted into the vagina. Similar in shape to the male condom, with a flexible ring||Applied immediately before intercourse, for single use||21|
|Condom, male||Latex or polyurethane sheath placed over erect penis, widely available in drugstores||Applied immediately before intercourse, for single use. Best protection against sexually transmitted diseases||11|
|Depo-Provera injection||Injection that inhibits ovulation, obtained by prescription||Injections performed at a doctor's office, once every three months||Less than 1|
|Diaphragm with spermicide||Dome-shaped rubber disk that covers the cervix, obtained by prescription||Inserted before intercourse and left in place at least six hours after||17|
|Douching||Use an over-the-counter feminine douche immediately after intercourse in an effort to wash out the sperm||Sperm travel quickly to the cervix, making this an ineffective method of birth control||40|
|IUD (intrauterine device)||T-shaped device inserted in the uterus during a visit to the doctor||Can remain in place for up to one or 10 years, depending on type||Less than 1|
|Morning-after pill (emergency contraceptive)||Pills similar to regular birth control pills, obtained by prescription||Must be taken within 72 hours of unprotected intercourse||80% reduction in pregnancy risk|
|Patch||Adhesive patch worn on the skin that releases hormones preventing ovulation. Obtained by prescription||New patch is applied once a week for three weeks, followed by one week without the patch||1-2|
|Periodic abstinence||Refraining from intercourse when conception is likely||Requires regular menstrual cycles and close monitoring of body functions pertaining to ovulation||20|
|Spermicide alone||A foam, cream, jelly, film, or suppository, or tablet containing nonoxynol-9||Depending on product, inserted between five and 90 minutes before intercourse; usually left in place at least six to eight hours after||20-50, depending on product|
|Withdrawal||Having intercourse, but removing the male penis before ejaculation||Not recommended for teens, and some seminal fluid leaks before ejaculation, making it an ineffective method of birth control||27|
- Spermicides: Some women and men are allergic to spermicides or find them irritating to the skin.
- IUD: The device is a foreign object that stays inside the uterus, and the uterus tries to get it out. A woman may have heavier menstrual periods and more menstrual cramping with an IUD in place.
- Tubal ligation: Some women report increased menstrual discomfort after this surgery. It is not known if this side effect is related to the tubal ligation itself.
Nearly 60 percent of sexually active girls under age 18 would discontinue at least some reproductive health services if their parents were informed that they were seeking contraceptive services, according to a study published in the August 14, 2002 issue of the Journal of the American Medical Association (JAMA). If parental notification would cause the majority of minor girls to stop seeking reproductive health services or to use less effective methods of contraception, the rates of teen pregnancies and STD infections would substantially increase, Carol Ford of the Adolescent Medicine Program at the University of North Carolina–Chapel Hill and Abigail English of the Center for Adolescent Health & the Law state in an accompanying JAMA editorial. Although there is widespread consensus that communication between adolescents and their parents about sexual decision-making is important, there is no reason that confidential reproductive health care and efforts to improve communication between parents and their adolescent children cannot occur simultaneously, these authors suggest.
Parents of adolescents often are concerned that distribution of contraceptives leads to increased sexual activity. However, a study of 4,100 high school students published in the June 2003 issue of the American Journal of Public Health found that students who had access at school to condoms and instructions on their proper use were no more likely to have sexual intercourse than students at schools without condom distribution programs.
Fallopian tubes —The pair of narrow tubes leading from a woman's ovaries to the uterus. After an egg is released from the ovary during ovulation, fertilization (the union of sperm and egg) normally occurs in the fallopian tubes.
Fertilization —The joining of the sperm and the egg; conception.
Implantation —The process in which the fertilized egg embeds itself in the wall of the uterus.
Ovulation —The monthly process by which an ovarian follicle ruptures releasing a mature egg cell.
See also Condom .
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Advocates for Youth. 2000 M St. NW, Suite 750, Washington, DC 20036. Web site http://www.advocatesforyouth.org.
Planned Parenthood Federation of America Inc. 434 W. 33rd St., New York, NY 10001. Web site: http://www.plannedparenthood.org.
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Amy B. Tuteur Ken R. Wells