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Medical Specializations


Surgery => Gynecology => Birth Control


Birth Control


INTRODUCTION
Birth Control or Contraception, deliberate prevention of pregnancy using any of several methods. Family planning is a more encompassing phrase that refers to the process of making decisions about when and how many children to have, and choosing strategies to achieve these goals.

In the United States, about 64 percent of women 15 to 44 years old practice birth control. When no birth control is used about 85 percent of sexually active couples experience a pregnancy within one year.

BIRTH CONTROL METHODS
Selecting a birth control method is a personal decision. It requires sexually active males and females to consider a variety of factors, including individual preferences for convenience and comfort; medical histories; and the risks, benefits, and side effects associated with each method. A further consideration is whether a couple ever plans to have children. Most birth control methods are reversible-that is, after discontinuing the use of birth control, most men and women will still be fertile, or able to reproduce. Surgical birth control methods cannot, in most cases, be reversed; once the surgery is performed, the male or female can not reproduce.

No birth control method is 100 percent effective in preventing pregnancy, although some methods are more effective than others. Pregnancy rates for birth control methods, also known as failure rates, are usually given as a percentage that represents the number of pregnancies expected in a group of 100 women using the method for one year. Scientists use two types of pregnancy rates when describing a birth control method's effectiveness. Method effectiveness, or perfect use, is the chance of becoming pregnant when a particular method is used correctly and consistently with each act of sexual intercourse. User effectiveness, or typical use, is the percentage of pregnancies that result from average use of the method, which accounts for improper or inconsistent use. This article provides an overview of birth control methods and provides typical use statistics. For further detail, see the articles on individual methods.

° Barrier Methods
Barrier methods provide physical barriers that keep the sperm from entering the uterus. These methods include the male and female condoms, the diaphragm, and the cervical cap.

The male condom (also called a prophylactic) is a thin sheath made of latex, or less commonly, animal membrane, that fits over an erect penis. The condom is inexpensive, easy to use, does not require a prescription, and has no known side effects. It is currently one of the most popular forms of reversible contraception in the United States.

Male condoms made of latex also protect users against sexually transmitted diseases (STDs) including human immunodeficiency virus (HIV), which causes acquired immune deficiency syndrome (AIDS). In typical use, male condoms are 84 percent effective in preventing pregnancy. Using a spermicide (cream, foam, or jelly that kills sperm) with a condom greatly improves user effectiveness.

The female condom, available since 1994 in the United States, is an elongated polyurethane sac with a ring on each end. One ring is inserted into the vagina, while the other ring remains outside, partially covering the external genital organs. With typical use, the female condom is 79 percent effective in preventing pregnancy. It is not yet clear how much protection the female condom provides against STDs.

Like the male condom, the female condom is available without a prescription. In both cases, a new condom must be used for each act of intercourse.
The diaphragm is a shallow, molded cup of thin rubber with a flexible rim. Before intercourse, spermicide must be placed inside the cup and around the inside of the rim of the diaphragm. The woman then inserts the diaphragm into her vagina so that it covers the cervix (the opening of the uterus into the vagina). The diaphragm is held in place by vaginal muscles and pubic bone where it prevents the passage of sperm from the vagina to the uterus. The spermicide kills any sperm that are able to pass by the diaphragm. Diaphragms come in various sizes to fit the cervix. They are available only from health care professionals who ensure that the device fits properly. In typical use, the diaphragm is about 82 percent effective in preventing pregnancy.
The cervical cap is smaller than a diaphragm and fits directly onto the cervix where it is held in place by suction. It must be fitted by a health care professional and also used with a spermicide. When used with spermicide, the cervical cap, like the diaphragm, is about 82 percent effective in preventing pregnancy.

Barrier methods cause few side effects, although some users may have allergic reactions to the rubber or spermicide. Some people feel barrier methods are inconvenient because they interfere with sexual spontaneity.

° Spermicides
Spermicides are jellies, creams, foams, suppositories, tablets, or films that contain a sperm-killing chemical. They can be purchased without a prescription and used with or without a condom, diaphragm, or cervical cap. Spermicides used alone must be inserted into the vagina before each act of intercourse and a woman should not douche for six to eight hours after intercourse. The timing of application depends on the brand of spermicide used. In typical use, spermicides are effective in preventing pregnancy 70 percent of the time. They may cause an allergic reaction such as irritation of the vagina or penis. Spermicide can also kill some STD organisms.

° Intrauterine Device
The intrauterine device (IUD) is a small plastic device inserted into the uterus to prevent pregnancy. It may also contain an insert with the hormone progesterone or a partial copper covering. IUDs work either by interfering with the ability of sperm to fertilize an egg or preventing a fertilized egg from implanting in the lining of the uterus.

An IUD must be inserted and removed by a health care professional. A plastic string attached to the IUD hangs down through the cervix, allowing a woman to check regularly that the IUD is properly positioned. A missing string may indicate that the IUD has moved out of place. In typical use, the IUD is 96 percent effective in preventing pregnancy. The device can cause pelvic inflammatory disease (PID), an infection of the reproductive tract, and increased menstrual bleeding and cramping. Other possible side effects include an allergic reaction to copper, perforation of the uterus, and embedding of the IUD in the uterus. An ectopic pregnancy, the implantation of a fertilized egg outside of the uterus, is a serious complication that occurs rarely.

° Hormonal Contraceptives
Hormonal contraceptives deliver doses of female sex hormones that interfere with ovulation (maturation and release of an egg from the ovaries) and affect the condition of the uterine lining to prevent fertilized eggs from implanting in it. These hormones may be administered in pill form, through skin implants, or by injection. Each type is available only by prescription. Hormonal contraceptives are extremely effective methods for preventing pregnancy when used properly and use of them does not interfere with sexual spontaneity. This form of birth control does not, however, protect against STDs.

Birth control pills, or oral contraceptives, were first approved for use in the United States in 1960. These early pills, known as combination pills, contained both estrogen and progestin (a synthetic form of progesterone). In 1973 progestin-only pills also became available.

To prevent pregnancy a woman takes birth control pills for 21 days, after which she takes no pill or a placebo, a pill containing no hormones, for 7 days. The pill works by preventing ovulation, thickening the mucus in the cervix to interfere with the sperm, and preventing the lining of the uterus from thickening so that a fertilized egg can not implant in it. In typical use, the pill is 94 percent effective in preventing pregnancy. This form of contraception does not interfere with intercourse. In addition, it can relieve menstrual pain and reduce menstrual bleeding, and it may 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), headaches, hypertension, weight gain, mood changes, decreased sexual desire, blood clotting disorders, cardiac complications, breast tenderness, galactorrhea (discharge of milk from the breast), and drug interactions.

Emergency contraceptive pills, commonly called morning after pills, prevent pregnancy after unprotected intercourse. Prescribed by a health care professional, these pills are similar to birth control pills but contain a higher dose of hormones. A woman takes the pills within 72 hours of unprotected intercourse and usually takes a second dose 12 hours later. Depending on where a woman is in her menstrual cycle at the time she takes these contraceptives, the pills will either inhibit or delay ovulation, or they may alter the uterine lining, preventing implantation of a fertilized egg. Studies indicate that emergency contraceptive pills can prevent pregnancy 75 percent of the time. In the United States, drug manufacturers received approval to package and market morning-after pills in 1997.
Hormonal implants, known by the brand name Norplant, were approved in the United States in 1990 for pregnancy prevention. Six flexible, matchstick-sized tubes filled with progestin are implanted by a physician just under the skin of a woman's arm and can remain in place up to five years. Adverse side effects include infection at the insertion point, excess bleeding or bleeding between menstrual periods, headaches, weight changes, breast tenderness, galactorrhea, irregular menstrual periods, and acne.
Contraceptive injections, known by the brand name Depo-Provera, a synthetic form of progesterone called medroxyprogesterone acetate, are injected into the muscles of the buttocks or arm every three months. It was approved for contraceptive use in the United States in late 1992. Adverse side effects include weight gain, menstrual irregularities, headaches, depression, blood clotting disorders, hot flashes, decreased sexual desire, breast pain, and acne.

Both Norplant and Depo-Provera are highly effective contraceptive methods. With typical use they are both 99 percent effective in preventing pregnancy.

° Surgical Sterilization Methods of surgical sterilization, vasectomy for men and tubal ligation for women, are almost 100 percent effective in preventing pregnancy. They do not protect against STDs, however. These surgical procedures are permanent forms of birth control. Although surgical techniques may be used to reverse vasectomy or tubal ligation in some cases, no one should undergo sterilization with the expectation that it can later be reversed.

Vasectomy is performed in a doctor's office or clinic using local anesthesia. Two small incisions are made in the scrotum (the sac below the penis that contains the testes), and the vasa deferentia (singular, vas deferens), the ducts that carry sperm from the testes to the penis) are cut and the ends tied off to prevent sperm from reaching the penis.
Tubal ligation is a more complicated procedure performed under general or spinal anesthesia or local anesthesia with a sedative. The Fallopian tubes are blocked or cut and tied to prevent eggs from descending from the ovary to encounter sperm.

° Natural Family Planning
Natural family planning, also called fertility awareness or the rhythm method, relies on abstinence from sexual intercourse during the most fertile phase of a woman's menstrual cycle. This period ranges from five days before ovulation to two days after ovulation. One technique for determining fertility is the basal body temperature method, in which a woman takes her temperature at the same time each morning before getting out of bed. In most women, body temperature rises about one degree on the day of ovulation and stays raised for several days. The cervical mucus method of determining fertility requires a woman to monitor the consistency of her cervical mucus. Mucus that is clear, wet, and sticky or elastic indicates fertility.
In typical use, natural family planning methods are generally about 81 percent effective in preventing pregnancy. Effectiveness varies depending on the specific method used. These methods are generally accepted by religions that ban contraceptives. These techniques cause no side effects, require minimal equipment, and are inexpensive. Natural family planning requires a high level of commitment to consistently and accurately monitor fertility. Some couples find abstinence from sexual intercourse during the fertile period inconvenient. In addition, natural family planning does not provide protection against STDs.

° Withdrawal
Withdrawal (coitus interruptus) is the deliberate removal of the penis from the vagina before ejaculation so that sperm is not deposited in or near the vagina. This method of contraception is not recommended, because drops of fluid secreted by the penis when it first becomes erect can contain enough sperm to cause pregnancy. In addition, a man may not withdraw in time. The penis should not be reinserted into the vagina after ejaculation because sperm may remain in the urethra. In typical use, withdrawal is effective in preventing pregnancy 76 percent of the time. It does not protect against STDs.

° Abstinence
Abstinence is the avoidance of any sexual activity that could cause pregnancy. This includes intercourse and other sexual activities in which semen may come in contact with the vulva (external female genitals) or vagina. Abstinence is completely effective in preventing pregnancy as well as STDs, and it poses no health risks.

CURRENT RESEARCH IN BIRTH CONTROL
A new male condom made of polyurethane is one type of birth control currently under development. Researchers are designing it to feel more natural and be more durable than the latex condom. New spermicidal preparations are also being tested that would better protect against HIV and other STD organisms. Diaphragms may one day include a one-size-fits-all device and disposable, spermicide-releasing diaphragms may also be developed. Other research is focusing on biodegradable hormonal implants designed to dissolve in the body and hormonal contraceptive injections and implants for men.

A contraceptive vaccine for men currently in development contains a hormone that appears to interfere with the production of both sperm and the male sex hormone testosterone. More promising may be a vaccine that eliminates sperm production but that does not affect testosterone levels.

Vaginal rings that deliver female sex hormones are another potential method for preventing pregnancy. These silicone rubber rings fit in the vagina and release a steady supply of hormones. Progestin-only vaginal rings would be worn continuously while those containing both estrogen and progestin would be worn for three weeks and then removed for one week to allow menstrual bleeding in the same pattern as combined oral contraceptives. These devices may last for three months to one year.

HISTORY AND SOCIAL ISSUES OF BIRTH CONTROL
A variety of birth control methods have been used throughout history and across cultures. In ancient Egypt women used dried crocodile dung and honey as vaginal suppositories to prevent pregnancy. One of the earliest mentions of contraceptive vaginal suppositories appears in the Ebers Medical Papyrus, a medical guide written between 1550 and 1500 BC. The guide suggests that a fiber tampon moistened with an herbal mixture of acacia, dates, colocynth, and honey would prevent pregnancy. The fermentation of this mixture can result in the production of lactic acid, which today is recognized as a spermicide.

Before the introduction of the modern birth control pill, women ate or drank various substances to prevent pregnancy or induce miscarriage. The seeds of Queen Anne's lace, pennyroyal, giant fennel, and many other concoctions of plants and herbs were used as oral contraceptives. However, such folk remedies can be dangerous or even fatal.

The concept of the IUD was developed by ancient Turks and Arabs who inserted smooth pebbles into the uterus of a camel to prevent it from getting pregnant during treks across the desert. Although the use of colorful penis coverings can be traced back to ancient Egypt, it is likely that their function was more decorative than contraceptive. In the 16th century the Italian anatomist Fallopius (for whom the tubes that carry the eggs from the ovary to the uterus were named) described linen sheaths to be used to protect against syphilis. Condoms made of sheep intestines were created by a physician in the court of King Charles II of England. Casanova is said to have referred to the device as an "English riding coat." It was not until after the vulcanization of rubber in 1844 that the condom was widely used as a birth control device.
The availability of vulcanized rubber was also important to the promotion of the diaphragm as a contraceptive method. The modern diaphragm was invented in 1838 by a German physician. The cervical cap was invented in 1860, but it did not receive the approval of the Food and Drug Administration for use in the United States until the late 1980s, despite its widespread use in Europe.
Concerns about overpopulation have also existed since ancient times. The Greek philosophers Plato and Aristotle warned of its dangers. In his essay De Anima, Roman philosopher Tertullian commented on the blessing of catastrophes that help curb overpopulation. The British economist Thomas Malthus, however, made overpopulation a topic of scholarly discussion. He was one of the first to apply statistics to the analysis of population growth. This approach became the science of demography. Malthus was concerned about the human potential to produce offspring in far greater numbers than the earth's ability to provide subsistence. In his Essay on the Principle of Population, published in 1798, Malthus advocated what he termed "moral restraint" in the form of strict premarital chastity and delayed marriage to curb population growth. Malthus's views were attacked by many as pessimistic, unsympathetic to the poor, and unrealistic in terms of his proposed solution. The birth control movement grew out of Malthus's concerns, and his successors advocated more practical methods of contraception.

Margaret Sanger, an American nurse, pioneered the modern birth control movement in the United States. In 1912 she began publishing information about women's reproductive concerns through magazine articles, pamphlets, and several books. In 1914 Sanger was charged with violation of the Comstock Law, federal legislation passed in 1873 prohibiting the mailing of obscene material including information about birth control and contraceptive devices. In defiance of the Comstock Law and despite being jailed for these activities, Sanger continued to publish and disseminate information about birth control. She and her sister Ethel Byrne opened the first of several birth control clinics in America on October 16, 1916, in Brooklyn, New York.
The Comstock Law was revised by Congress in 1936 to exclude birth control information and devices. Many states had laws prohibiting distribution or use of contraceptives but the constitutionality of these laws was increasingly questioned. In 1965, in Griswold v. Connecticut, the Supreme Court of the United States ruled that married people have the right to practice birth control without government intervention. In 1972, in Eisenstadt v. Baird, the court held that unmarried people have the same right.

Today there are more birth control options than ever before, but overpopulation and unwanted pregnancies remain worldwide problems. Having more children than one can support may lead to poverty, malnutrition, illness, and high mortality rates for infants, children, and women.
The problem of teenage pregnancy is considerably worse in the United States than in almost any other developed country. Studies show that birth rates for women under 20 are higher in the United States than in 29 other developed countries. A detailed study comparing Canada, England and Wales, France, The Netherlands, Sweden, and the United States suggested that the problem of teen pregnancy in the United States may be related to less sex education in schools and lower availability of contraceptive services and supplies to adolescents. This study counters the view of people in the United States who argue that sex education or making contraceptives such as condoms available to school-age children promotes sexual activity.

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