Oral contraceptives are medicines taken by mouth to help prevent
pregnancy. They are also known as the pill, OCs, or birth control pills.
Oral contraceptives, or birth control pills, contain synthetic forms of
two hormones produced naturally in the body. These hormones, estrogen and
progestin, regulate the female menstrual cycle. Some types of oral
contraceptives use only progestational hormones, but most use a
combination of estrogen and progestin. As of 2004, there were three types
of oral contraceptives marketed:
The goal of the biphasic and triphasic formulations is to achieve adequate
control of the menstrual cycle while using lower doses of both estrogens
and progestins, thereby reducing the risk of adverse effects. Reviews of
controlled studies have not demonstrated a clear advantage of the newer
formulations over the older monophasic drugs.
When taken in the proper amounts, following a specific schedule, oral
contraceptives are very effective in preventing pregnancy. Studies show
that fewer than one of every 100 females who use oral contraceptives
correctly becomes pregnant during the first year of use.
These pills have several effects that help prevent pregnancy. For
pregnancy to occur, an egg must become mature inside a woman's
ovary, be released, and travel to the fallopian tube. Sperm must travel
through the reproductive track to fertilize the egg in the fallopian tube.
Then the fertilized egg must travel to the woman's uterus (womb),
where it lodges in the uterus lining and develops into a fetus.
The main way that oral contraceptives prevent pregnancy is by keeping an
egg from ripening fully. Eggs that do not ripen fully cannot be
fertilized. In addition, birth control pills thicken mucus in the
woman's body through which the sperm has to swim. Thus it is more
difficult for the sperm to reach the egg. Oral contraceptives also change
the uterine lining so that a fertilized egg cannot lodge there to develop.
is the primary use of these medications, they may also be used to treat
adolescent and post-adolescent
in girls. Some products have this as part of their official indications,
but others may be used as well.
No form of birth control (except abstinence from sexual intercourse) is
100 percent effective. However, oral contraceptives can be highly
effective when used properly. Teens and young women who anticipate having
sexual intercourse should discuss the options with a healthcare
Oral contraceptives do not protect against
sexually transmitted diseases
. For some protection against such diseases, teenage males and young men
need to use a latex
. Also, oral contraceptives are not effective immediately after a young
woman begins taking them. Physicians recommend using other forms of birth
control for the first one to three weeks. Then users should follow the
instructions of the physician who prescribed the medicine.
cigarettes while taking oral contraceptives greatly increases the risk of
serious side effects. Females who take oral contraceptives should not
Seeing a physician regularly while taking this medicine is very important.
The physician will note unwanted side effects, and patients should follow
his or her advice on how often they should be seen.
Young women who take oral contraceptives should be sure to tell the
healthcare professional in charge before they undergo surgical or dental
procedures, laboratory tests, or emergency treatment.
This medicine may increase sensitivity to sunlight. Females using oral
contraceptives should avoid too much sun exposure and should not use
tanning beds, tanning booths, or sunlamps until they know how the medicine
affects them. Some females taking oral contraceptives may get brown
splotches on exposed areas of their skin. These usually go away over time
after the women stop taking birth control pills.
Oral contraceptives may cause the gums to become tender and swollen or to
bleed. Careful brushing and flossing, gum massage, and regular cleaning
may help prevent this problem. Users should check with a physician or
dentist if gum problems develop.
Serious side effects are rare in healthy females who do not smoke
cigarettes. In women with certain health problems, however, oral
contraceptives may cause problems such as liver
, noncancerous liver tumors, blood clots, or
. Healthcare professionals can help prospective users weigh the benefits
of being protected against unwanted pregnancy against the risks of
possible health problems.
The most common minor side effects are
, abdominal cramping or bloating, breast
, tenderness or swelling, swollen ankles or feet, tiredness, and acne.
These problems usually go away as the body adjusts to the drug and do not
need medical attention unless they continue or they interfere with normal
activities. Other side effects should be brought to the attention of the
physician who prescribed the medicine. Teens and young women should check
with the physician as soon as possible if any of the following side
Women who have any of the following symptoms should get emergency help
right away. These symptoms may be signs of blood clots:
The adverse effects of oral contraceptives can be impossible to predict.
Other than avoiding smoking, there are no effective means of preventing
side effects. All observed adverse effects should be reported to a
Oral contraceptives may continue to affect the menstrual cycle for some
time after a young woman stops taking them. Women who miss periods for
several months after stopping this medicine should check with their
physicians. Other rare side effects may occur. Anyone who has unusual
symptoms while taking oral contraceptives should get in touch with her
A doctor explains to a teenage girl how to use birth control pills.
(© LWA-Stephen Welstead/Corbis.)
—An abnormal sac or enclosed cavity in the body filled with
liquid or partially solid material. Also refers to a protective,
walled-off capsule in which an organism lies dormant.
—A condition in which the tissue that normally lines the uterus
(endometrium) grows in other areas of the body, causing pain, irregular
bleeding, and frequently, infertility.
—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
—In humans, the developing organism from the end of the eighth
week to the moment of birth. Until the end of the eighth week the
developing organism is called an embryo.
—A non-cancerous tumor of connective tissue made of elongated,
threadlike structures, or fibers, which usually grow slowly and are
contained within an irregular shape. Fibroids are firm in consistency
but may become painful if they start to break down or apply pressure to
areas within the body. They frequently occur in the uterus and are
generally left alone unless growing rapidly or causing other problems.
Surgery is needed to remove fibroids.
—A chemical messenger secreted by a gland or organ and released
into the bloodstream. It travels via the bloodstream to distant cells
where it exerts an effect.
—A condition in which the skin and whites of the eyes take on a
yellowish color due to an increase of bilirubin (a compound produced by
the liver) in the blood. Also called icterus.
—A throbbing headache that usually affects only one side of the
head. Nausea, vomiting, increased sensitivity to light, and other
symptoms often accompany a migraine.
—The thick fluid produced by the mucous membranes that line many
body cavities and structures. It contains mucin, white blood cells,
water, inorganic salts, and shed cells, and it serve to lubricate body
parts and to trap particles of dirt or other contaminants.
—One of the two almond-shaped glands in the female reproductive
system responsible for producing eggs and the sex hormones estrogen and
Pelvic inflammatory disease (PID)
—Any infection of the lower female reproductive tract (vagina and
cervix) that spreads to the upper female reproductive tract (uterus,
fallopian tubes and ovaries). Symptoms include severe abdominal pain,
high fever, and vaginal discharge. PID is the most common and most
serious consequence of infection with sexually transmitted diseases in
women and is a leading cause of female fertility problems.
—The female reproductive organ that contains and nourishes a
fetus from implantation until birth. Also called the womb.
Parents become concerned that teens who use oral contraceptives are at
risk of becoming sexually active. Although studies have been limited, they
have failed to
show that availability of oral contraceptives leads to an increase in
sexual activity among adolescent girls.
Oral contraceptives do not protect against sexually transmitted diseases.
When used for contraception, they should be limited to monogamous
Although the list of potential side effects and adverse effects is very
long and contains some severe risks, the actual frequency of these risks
is low. In most cases, oral contraceptives have a very high safety margin.
Mcevoy, Gerald K., et al.
AHFS Drug Information 2004
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Siberry, George K., and Robert Iannone, eds.
The Harriet Lane Handbook
, 15th ed. Philadelphia: Mosby, 2000.
Kaunitz, Andrew M. "Enhancing oral contraceptive success: The
potential of new formulations."
American Journal of Obstetrics & Gynecology
190, no. 4, Suppl. (April 2004): S23–S29.
American Academy of Dermatology.
PO Box 4014, Schaumburg, IL 60168–4014. Web site:
American Board of Obstetrics and Gynecology.
2915 Vine Street, Dallas, TX 75204. Web site:
Planned Parenthood Federation of America.
434 West 33rd St., New York, NY 10001. Web site:
"Update on Oral Contraceptives."
American Family Physician.
Available online at http://www.aafp.org/afp/991101ap/html
(accessed September 28, 2004).