Contraception
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If you and your partner don't want to have a baby at this time, there are
many different products that can help prevent pregnancy.
The types of birth control that are most reliable for preventing pregnancy
are birth control pills, injections, implants, IUDs, and sterilization. Of
every 100 women who use one of these types of birth control for a year, about
1 to 5 women will become pregnant.
Latex condoms for men and diaphragms with spermicide are less effective.
Of every 100 women who rely on them for a year, about 14 to 20 will become
pregnant. Other methods of birth control, such as spermicide alone, female
condoms, and natural family planning, don't work as well.
Some types of birth control are available without a doctor's prescription.
They have no side effects for most people. But some people may be allergic
to them and get rashes if they use them.
People sometimes call condoms for men rubbers, safes, or prophylactics.
You can buy condoms without a prescription at drugstores, supermarkets, and
many other places.
To use, put the condom on the erect penis before having sex. Use each condom
only once. Most condoms are made from latex rubber. Others are made from
lamb intestines and are often called lambskins. Some condoms are made from
polyurethane. If you aren't allergic to latex, you should use latex condoms
because they are best at preventing pregnancy and they also protect best
against AIDS, herpes, and other sexually transmitted diseases (STDs). Condoms
shouldn't be used with Vaseline or other brands of petroleum jelly, lotions,
or oils. But they can be used with lubricants that don't have oil, such as
K-Y jelly.
The Reality Female Condom is made of polyurethane. You can buy female condoms
at drugstores without a prescription. To use, insert the condom into the
vagina right before sex and use each only once. Don't use it at the same
time as a male condom. If you have a choice, it's better for the man to use
a latex condom because it's better than the female condom at preventing pregnancy
and protecting you against STDs.
Spermicides are available without a prescription in drugstores and some
other stores. They contain a chemical that kills sperm. Spermicides are sold
in several forms including foam, cream and jelly.
To use, put the spermicide into the vagina at least 10 minutes before having
sex. One dose of spermicide usually works for one hour, but you must use
another dose every time you have intercourse even if less than an hour has
passed. You should not douche or rinse your vagina for at least 6 to 8 hours
after having sex.
The risks and benefits of different forms of birth control are different
for each person. So it's best to decide with your doctor which form of birth
control is best for you.
The diaphragm with spermicide is put into the vagina before sex so that
it covers the cervix, or neck of the womb. Put the spermicide into the dome
of the diaphragm before inserting it. You must be fitted for a diaphragm
at a doctor's office or clinic because diaphragms come in several different
sizes. The diaphragm must stay in place at least 6 hours after intercourse,
but not for more than 24 hours. If you have sex more than once while wearing
the diaphragm, you must add more spermicide without taking the diaphragm
out. Spermicide is available without a prescription at drugstores.
The cervical cap is a soft rubber cup with a round rim that is put into
the vagina to fit over the cervix, or neck of the womb. The cap is smaller
than the diaphragm, but sometimes more difficult to insert. You must go to
your doctor or clinic to be fitted for the cervical cap. It comes in several
different sizes. The cervical cap must be used with spermicide, which is
available in drugstores without a prescription. You can leave it in place
for 48 hours.
You need a doctor's prescription to get birth control pills, also called
oral contraceptives. There are two types of birth control pills: "combined
oral contraceptives" and "minipills."
Combined oral contraceptives have a combination of two hormones--estrogen
and progestin. They work by keeping the ovaries from releasing an egg. The
pill must be taken every day.
Minipills contain only one hormone, progestin. They work by thickening
the cervical mucus to keep sperm from reaching the egg. Sometimes they also
keep the ovaries from releasing an egg. You must take one pill every day.
Minipills are slightly less effective than combined oral contraceptives.
Depo-Provera
Depo-Provera is a form of progestin, similar to the hormone in the minipill.
Depo-Provera must be injected with a needle into the woman's buttocks or
arm muscle by a doctor. You must get an injection every three months for
the birth control to continue to work.
Norplant
Norplant is a form of progestin that is placed under the skin. Norplant
is made of rubber rods that look like matchsticks. A doctor places the rods
under the skin of the woman's upper arm, where they slowly release progestin.
A doctor must also remove the rods. There are two types of Norplant. The
six-rod Norplant gives birth control for up to five years. The two-rod Norplant
gives birth control for up to two years.
IUDs
An IUD (Intrauterine Device) is inserted into the womb by a doctor. Two
types of IUDs are now used in the United States: the Paragard Copper T 380A,
which releases copper, and the Progestasert Progesterone T, which releases
progesterone, a form of progestin. The Paragard IUD can stay in place for
10 years. The Progestasert must be replaced every year. A doctor must remove
it.
Outpatient surgery is necessary to make a man sterile, or unable to produce
enough sperm to make a woman pregnant. This is done by sealing, tying or
cutting the tube through which sperm travel to the penis from the testicles.
The operation usually takes less than 30 minutes and is done under local
anesthesia. Men who have vasectomies must be sure they will never want
to father children in the future.
Female sterilization is usually a longer operation than a vasectomy, though
it may sometimes be done as outpatient surgery. It is usually done under
general anesthesia. The surgery involves tying, cutting or blocking the fallopian
tubes so eggs can't reach the womb. Women who have this surgery must be sure
they will never want to have a baby in the future.
This is also known as fertility awareness or periodic abstinence. For this
method to work, a man and woman cannot have sex on the days the woman can
become pregnant unless using another form of birth control. These days usually
include from seven days before the woman ovulates (releases an egg) to three
days after she ovulates. A woman can ask her doctor how to tell when she
ovulates. This is done by taking into account when the last menstrual period
began, changes in body temperature, and changes in vaginal mucus.
The only kind of birth control that is also highly effective in preventing
AIDS and other sexually transmitted diseases is the latex condom worn by
the man. The female condom can also give some protection, but it's not as
good as the latex condom for men. If you use other forms of birth control
but also want protection against AIDS and other sexually transmitted diseases,
the man should also use a latex condom.
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Failure Rates in this chart are based on information from
clinical trials submitted to the FDA during product reviews. This number
represents the percentage of women who become pregnant during the first year
of use of a birth control method. For methods that the FDA does not review,
such as periodic abstinence, numbers are estimated from published literature.
For comparison, about 85 out of 100 sexually active women who wish to become
pregnant would be expected to become pregnant in a year.
Serious medical risks from contraceptives, such as stroke related to oral
contraceptives, are relatively rare. This chart is a summary of important
information, including risks, about drugs and devices approved by the FDA
for contraception and sterilization. It is not intended to be used alone,
and a health professional should be consulted regarding any contraceptive
choice. Review product labeling carefully for more information on use of
these products.
FDA Approval Date: Latex: Use started before premarket
approval was required. Polyurethane: cleared in 1989; available starting
1995.
Description: A sheath placed over the erect penis blocking
the passage of sperm.
Failure Rate (number of pregnancies expected per 100 women
per year): 11 (a, b)
Some Risks: Irritation and allergic reactions (less likely
with polyurethane)
Protection from Sexually Transmitted Diseases (STDs): Except
for abstinence, latex condoms are the best protection against STDs, including
gonorrhea and AIDS.
Convenience: Applied immediately before intercourse; used
only once and discarded. Polyurethane condoms are available for those with
latex sensitivity.
Availability: Nonprescription
FDA Approval Date: 1993
Description: A lubricated polyurethane sheath shaped similarly
to the male condom. The closed end has a flexible ring that is inserted into
the vagina.
Failure Rate (number of pregnancies expected per 100 women
per year): 21
Some Risks: Irritation and allergic reactions
Protection from Sexually Transmitted Diseases (STDs): May
give some STD protection; not as effective as latex condom
Convenience: Applied immediately before intercourse; used
only once and discarded.
Availability: Nonprescription
FDA Approval Date: Use started before premarket approval
was required.
Description: A dome-shaped rubber disk with a flexible rim
that covers the cervix so that sperm cannot reach the uterus. A spermicide
is applied to the diaphragm before insertion.
Failure Rate (number of pregnancies expected per 100 women
per year): 17 (b, d, e)
Some Risks: Irritation and allergic reactions, urinary tract
infection. (c) Risk of toxic shock syndrome, a rare but serious infection,
when kept in place longer than recommended.
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: Inserted before intercourse and left in place
at least six hours after; can be left in place for 24 hours, with additional
spermicide for repeated intercourse.
Availability: Prescription
FDA Approval Date: 2002
Description: A dome-shaped rubber disk with a valve and
a loop that is held in place by the vaginal wall. Covers the upper vagina
and cervix so that sperm cannot reach the uterus. Spermicide is applied before
insertion.
Failure Rate (number of pregnancies expected per 100 women
per year): 15
Some Risks: Skin irritation, spotting, discomfort (female
and male partners), urinary tract infection. Theoretical risk of toxic shock
syndrome.
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: Inserted before intercourse and left in place
at least 8 hours after; can be left in place for up to 48 hours, with additional
spermicide for repeated intercourse.
Availability: Prescription
FDA Approval Date: Prentiff Cap--1988; FemCap--2003
Description: A soft rubber cup with a round rim, which fits
snugly around the cervix.
Failure Rate (number of pregnancies expected per 100 women
per year): Prentiff Cap--17; FemCap--23 (b, d, e)
Some Risks: Irritation and allergic reactions, abnormal Pap
test. (c) Risk of toxic shock syndrome, a rare but serious infection, when
kept in place longer than recommended.
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: May be difficult to insert; can remain in place
for 48 hours without reapplying spermicide for repeated intercourse.
Availability: Prescription
FDA Approval Date: 1983 (Not currently marketed)
Description: A disk-shaped polyurethane device containing
the spermicide nonoxynol-9.
Failure Rate (number of pregnancies expected per 100 women
per year): 14-28 (d, e)
Some Risks: Irritation and allergic reactions, difficulty
in removal. (c) Risk of toxic shock syndrome, a rare but serious infection,
when kept in place longer than recommended.
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: Inserted before intercourse and protects for
repeated acts of intercourse for 24 hours without additional spermicide;
must be left in place for at least six hours after intercourse; must be removed
within 30 hours of insertion. Is discarded after use.
Availability: Nonprescription; not currently marketed
FDA Approval Date: Use started before premarket approval
was required. Since November 2002, only one active ingredient has been allowed.
Description: A foam, cream, jelly, film, suppository, or
tablet that contains nonoxynol-9, a sperm-killing chemical
Failure Rate (number of pregnancies expected per 100 women
per year): 20-50 (studies have shown varying effectiveness rates)
Some Risks: Irritation and allergic reactions, urinary tract
infections (c)
Protection
from Sexually Transmitted Diseases (STDs): None
Convenience: Instructions vary; check labeling. Inserted
between 5 and 90 minutes before intercourse and usually left in place at
least six to eight hours after.
Availability: Nonprescription
FDA Approval Date: First in 1960; most recent in 2003
Description: A pill that suppresses ovulation by the combined
actions of the hormones estrogen and progestin. A chewable form was approved
in November 2003.
Failure Rate (number of pregnancies expected per 100 women
per year): 1-2
Some Risks: Dizziness; nausea; changes in menstruation,
mood, and weight; rarely, cardiovascular disease, including high blood pressure,
blood clots, heart attack, and strokes
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: Must be taken on daily schedule, regardless
of frequency of intercourse. Women using the chewable tablet must drink 8
oz. of liquid immediately after taking.
Availability: Prescription
FDA Approval Date: 1973
Description: A pill containing only the hormone progestin
that reduces and thickens cervical mucus to prevent the sperm from reaching
the egg.
Failure Rate (number of pregnancies expected per 100 women
per year): 2
Some Risks: Irregular bleeding, weight gain, breast tenderness,
less protection against ectopic pregnancy
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: Must be taken on daily schedule, regardless
of frequency of intercourse.
Availability: Prescription
FDA Approval Date: 2003
Description: A pill containing estrogen and progestin, taken
in 3-month cycles of 12 weeks of active pills followed by one week of inactive
pills. Menstrual periods occur during the 13th week of the cycle.
Failure Rate (number of pregnancies expected per 100 women
per year): 1-2
Some Risks: Similar to oral contraceptives--combined pill
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: Must be taken on daily schedule, regardless
of frequency of intercourse. Since users will have fewer periods, they should
consider the possibility that they might be pregnant if they miss scheduled
periods. May have more unplanned bleeding and spotting between periods than
with 28-day oral contraceptives.
Availability: Prescription
FDA Approval Date: 2001
Description: Skin patch worn on the lower abdomen, buttocks,
or upper body that releases the hormones progestin and estrogen into the
bloodstream.
Failure Rate (number of pregnancies expected per 100 women
per year): 1-2 (Appears to be less effective in women weighing more than
198 pounds.)
Some Risks: Similar to oral contraceptives--combined pill
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: New patch is applied once a week for three
weeks. Patch is not worn during the fourth week, and woman has a menstrual
period.
Availability: Prescription
FDA Approval Date: 2001
Description: A flexible ring about 2 inches in diameter
that is inserted into the vagina and releases the hormones progestin and
estrogen.
Failure Rate (number of pregnancies expected per 100 women
per year): 1-2
Some Risks: Vaginal discharge, vaginitis, irritation. Similar
to oral contraceptives--combined pill
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: Inserted by the woman; remains in the vagina
for 3 weeks, then is removed for 1 week. If ring is expelled and remains
out for more than 3 hours, another birth control method must be used until
ring has been used continuously for 7 days.
Availability: Prescription
FDA Approval Date: 1998-1999
Description: Pills containing either progestin alone or
progestin plus estrogen
Failure Rate (number of pregnancies expected per 100 women
per year): Almost 80 percent reduction in risk of pregnancy for a single
act of unprotected sex
Some Risks: Nausea, vomiting, abdominal pain, fatigue, headache
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: Must be taken within 72 hours of having unprotected
intercourse.
Availability: Prescription
FDA Approval Date: 1992
Description: An injectable progestin that inhibits ovulation,
prevents sperm from reaching the egg, and prevents the fertilized egg from
implanting in the uterus.
Failure Rate (number of pregnancies expected per 100 women
per year): less than 1
Some Risks (serious medical risks from contraceptives are
rare): Irregular bleeding, weight gain, breast tenderness, headaches
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: One injection every three months.
Availability: Prescription
FDA Approval Date: 2000
Description: An injectable form of progestin and estrogen
Failure Rate (number of pregnancies expected per 100 women
per year): less than 1
Some Risks: Changes in menstrual cycle, weight gain. Similar
to oral contraceptives--combined.
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: Injection given once a month.
Availability: Prescription
FDA Approval Date: 1990
Description: Six matchstick-sized rubber rods that are surgically
implanted under the skin of the upper arm, where they steadily release the
contraceptive steroid levonorgestrel.
Failure Rate (number of pregnancies expected per 100 women
per year): less than 1
Some Risks: Irregular bleeding, weight gain, breast tenderness,
headaches, difficulty in removal
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: Implanted and removed by health-care provider
in minor outpatient surgical procedure; effective for up to five years.
Availability: Prescription. In July 2002, Norplant's manufacturer
announced that it will no longer distribute the Norplant system. Women using
the system should contact their doctors about what their contraceptive options
will be after the five-year expiration date of their Norplant systems.
FDA Approval Date: 1976 (f)
Description: A T-shaped device inserted into the uterus
by a health professional.
Failure Rate (number of pregnancies expected per 100 women
per year): less than 1
Some Risks: Cramps, bleeding, pelvic inflammatory disease,
infertility, perforation of uterus
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: After insertion by physician, can remain in
place for up to one or 10 years, depending on type.
Availability: Prescription
FDA Approval Date: N/A
Description: To deliberately refrain from having sexual
intercourse during times when pregnancy is more likely.
Failure Rate (number of pregnancies expected per 100 women
per year): 20
Some Risks: None
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: Requires frequent monitoring of body functions
(for example, body temperature for one method).
Availability: Instructions from health-care provider
FDA Approval Date: Early 1970s (g)
Description: The woman's fallopian tubes are blocked so the
egg and sperm can't meet in the fallopian tube, preventing conception. (h)
Failure Rate (number of pregnancies expected per 100 women
per year): less than 1
Some Risks: Pain, bleeding, infection, other post-surgical
complications, ectopic (tubal) pregnancy.
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: One-time surgical procedure that requires an
abdominal incision.
Availability: Surgery
FDA Approval Date: 2002
Description: Small metallic implant that is placed into the
fallopian tubes. The device works by causing scar tissue to form, blocking
the fallopian tubes and preventing conception. (h)
Failure Rate (number of pregnancies expected per 100 women
per year): less than 1
Some Risks: Mild to moderate pain after insertion, ectopic
(tubal) pregnancy.
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: Minor surgical procedure, permanent sterilization.
Device is inserted through the vagina using a catheter. Women must rely on
another birth control method during the first three months, until placement
is confirmed with an X-ray procedure.
Availability: Prescription
FDA Approval Date: N/A
Description: Sealing, tying, or cutting a man's vas deferens
so that the sperm can't travel from the testicles to the penis. (h)
Failure Rate (number of pregnancies expected per 100 women
per year): less than 1
Some Risks (serious medical risks from contraceptives are
rare): Pain, bleeding, infection, other minor postsurgical complications
Protection from Sexually Transmitted Diseases (STDs): None
Convenience: One-time surgical procedure.
Availability: Surgery
(a) Projected from six-month study and adjusted for use of
emergency contraception.
(b) If spermicides are used with barrier methods, be sure
that the spermicide is compatible with the condom or diaphragm (won't cause
it to weaken or break). Oil-based lubricants (such as petroleum jelly or
baby oil) will cause latex to weaken and should not be used with these methods.
(c) Spermicides used alone, with barrier devices, or with
condoms can cause irritation to the skin lining the vagina, especially when
the spermicide is used frequently. There is a possibility that spermicide
might increase the risk of acquiring some sexually transmitted diseases because
of disruption of the vaginal skin. Spermicide has not been proven to be effective
against bacteria and viruses in people. Therefore, there is no reason to
use spermicide during pregnancy.
(d) Medications for vaginal yeast infections may decrease
effectiveness of spermicides.
(e) Less effective for women who have had a baby because the
birth process stretches the vagina and cervix, making it more difficult to
achieve a proper fit.
(f) First approval date of currently marketed IUDs. Some IUDs
were sold before premarket approval was required. Those products are no longer
on the market.
(g) Sold before premarket approval was required (1976).
(h) A contraceptive option for people who don't want children. Considered
permanent because reversal is typically unsuccessful.
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Introduction
Oral contraceptives (OCs) first became available to American women in the
early 1960s. The convenience, effectiveness, and reversibility of action
of birth control pills (popularly known as “the pill”) have made them the
most popular form of birth control in the United States. However, concerns
have been raised about the role that hormones might play in a number of cancers,
and how hormone-based OCs contribute to their development.
This fact sheet addresses only what is known about OC use and the risk of
developing cancer. It does not deal with the role of menopausal hormone use
or the most serious side effect of OC use—the increased risk of cardiovascular
disease for certain groups of women.
Oral Contraceptives
Currently, two types of OCs are available in the United States. The most
commonly prescribed OC contains two man-made versions of natural female hormones
(estrogen and progesterone) that are similar to the hormones the ovaries
normally produce. Estrogen stimulates the growth and development of the uterus
at puberty, causes the endometrium (the inner lining of the uterus) to thicken
during the first half of the menstrual cycle, and influences breast tissue
throughout life, but particularly from puberty to menopause.
Progesterone, which is produced during the last half of the menstrual cycle,
prepares the endometrium to receive the egg. If the egg is fertilized, progesterone
secretion continues, preventing release of additional eggs from the ovaries.
For this reason, progesterone is called the “pregnancy-supporting” hormone,
and scientists believe that it has valuable contraceptive effects. The man-made
progesterone used in OCs is called progestogen or progestin.
The second type of OC available in the United States is called the minipill.
It contains only a progestogen. The minipill is less effective in preventing
pregnancy than the combination pill, so it is prescribed less often.
Because medical research suggests that cancers of the female reproductive
organs depend on naturally occurring sex hormones for their development and
growth, scientists have been investigating a possible link between OC use
and cancer risk. Researchers have focused a great deal of attention on OC
users over the past 40 years. This scrutiny has produced a wealth of data
on OC use and the development of certain cancers, although results of these
studies have not always been consistent.
Breast Cancer
A woman’s risk of developing breast cancer depends on several factors, some
of which are related to her natural hormones. Hormonal factors that increase
the risk of breast cancer include conditions that may allow high levels of
hormones to persist for long periods of time, such as early age at first
menstruation (before age 12), late age at menopause (after age 55), having
children after age 30, and not having children at all.
Because many of the risk factors for breast cancer are related to natural
hormones, and because OCs work by manipulating these hormones, there has
been some concern about the possible effects of medicines such as OCs on
breast cancer risk, especially if women take them for many years. Sufficient
time has elapsed since the introduction of OCs to allow investigators to
study large numbers of women who took birth control pills for many years.
Even so, the results of some of these studies have not been consistent.
In an NCI-sponsored study published in 2003, researchers examined risk factors
for breast cancer among women ages 20 to 34 compared with women ages 35 to
54. Researchers analyzed data from 2,202 women who were diagnosed with breast
cancer between 1990 and 1992, and 2,209 women who did not have breast cancer.
The results indicated that the risk of breast cancer was significantly increased
for women ages 20 to 34 who had used OCs for at least 6 months. The risk
associated with OC use was strongest for women who had used OCs within 5
years of breast cancer diagnosis. Although also elevated, the risk was weaker
for women over age 35 and those who used OCs for longer periods of time.
A 1996 analysis of worldwide epidemiologic data conducted by the Collaborative
Group on Hormonal Factors in Breast Cancer found that women who were current
or recent users of birth control pills had a slightly elevated risk of developing
breast cancer. However, 10 years or more after they stopped using OCs, their
risk of developing breast cancer returned to the same level as if they had
never used birth control pills. In addition, breast cancers diagnosed in
women after 10 or more years of not using OCs were less advanced than breast
cancers diagnosed in women who had never used OCs. To conduct this analysis,
the researchers examined the results of 54 studies. The analysis involved
53,297 women with breast cancer and 100,239 women without breast cancer.
More than 200 researchers participated in this combined analysis of their
original studies, which represented about 90 percent of the epidemiological
studies throughout the world that had investigated the possible relationship
between OCs and breast cancer.
The return of risk to normal levels after 10 years or more of not taking
OCs was consistent regardless of family history of breast cancer, reproductive
history, geographic area of residence, ethnic background, differences in
study design, dose and type of hormone, and duration of use. The change in
risk also generally held true for age at first use; however, for reasons
that were not fully understood, there was a continued elevated risk among
women who had started to use OCs before age 20.
The findings of the Women’s Contraceptive and Reproductive Experience (Women’s
CARE) study were in contrast to those described above. The Women’s CARE study
examined the use of OCs as a risk factor for breast cancer in women ages
35 to 64. Researchers interviewed 4,575 women who were diagnosed with breast
cancer between 1994 and 1998, and 4,682 women who did not have breast cancer.
Investigators collected detailed information about the participants’ use
of OCs, reproductive history, health, and family history. The results, which
were published in 2002, indicated that current or former use of OCs among
women ages 35 to 64 did not significantly increase the risk of breast cancer.
The findings were similar for white and black women. Factors such as longer
periods of use, higher doses of estrogen, initiation of OC use before age
20, and OC use by women with a family history of breast cancer were not associated
with an increased risk of the disease.
Ovarian and Endometrial Cancers
Studies have consistently shown that using OCs reduces the risk of ovarian
cancer. In a 1992 analysis of 20 studies of OC use and ovarian cancer, researchers
from Harvard Medical School found that the risk of ovarian cancer decreased
with increasing duration of OC use. Results showed a 10- to 12-percent decrease
in risk after 1 year of use, and approximately a 50-percent decrease after
5 years of use. This association between OC use and decreased risk of ovarian
cancer has also been observed among women who have certain genetic changes
in the BRCA1 or BRCA2 gene that increase their risk of ovarian cancer.
The results of the Cancer and Steroid Hormone Study (CASH), which was conducted
by the Centers for Disease Control and Prevention and published in 1987,
indicated that the longer a woman had used OCs, the lower her risk of ovarian
cancer. The decrease in risk persisted long after OC use stopped. The risk-reducing
effect of OCs appeared in both older and younger women, and in women with
and without children. Several hypotheses have been offered to explain how
oral contraceptives might protect against ovarian cancer, such as a reduction
in the number of ovulations a woman has during her lifetime, but the exact
mechanism is still not known.
Researchers have also found that OC users have a reduced risk of endometrial
cancer. Findings from the CASH study and other reports show that combination
OC use can protect against the development of endometrial cancer. The level
of risk reduction is greater in women who have used OCs for a longer time,
and the protection apparently persists after women have stopped taking OCs.
The reduction in risk of ovarian and endometrial cancers from OC use does
not apply to the sequential type of pill, in which each monthly cycle contains
16 estrogen pills followed by 5 estrogen-plus-progesterone pills. (Sequential
OCs were taken off the market in 1976, so few women have been exposed to
them.) Researchers believe OCs reduce ovarian and endometrial cancer risk
only when the estrogen content of birth control pills is balanced by progestogen
in the same pill.
Cancer of the Cervix
There is evidence that long-term use of OCs (10 or more years) may be associated
with an increased risk of cancer of the cervix (the narrow, lower portion
of the uterus). A 2003 analysis by the International Agency for Research
on Cancer found an increased risk of cervical cancer with longer use of OCs.
Researchers analyzed data from 28 studies that included 12,531 women with
cervical cancer. The data suggested that the risk of cervical cancer may
decrease after OC use stops. However, more research is needed to determine
the extent to which women remain at risk for cervical cancer after they stop
using OCs.
Human Papillomavirus (HPV)
Of the more than 100 types of human papillomavirus (HPV), over 30 types
can be passed from one person to another through sexual contact. HPVs are
some of the most common sexually transmitted infections. Approximately 15
HPVs are known to cause cervical cancer. Compared to non-OC users, women
who use OCs may be less likely to use barrier methods of contraception (such
as condoms). Because condoms are partially effective in preventing HPV infection,
OC users who do not use condoms may be at increased risk of becoming infected
with HPV. Therefore, the increased risk of cervical cancer that some studies
found to be caused by prolonged OC use may actually be the result of HPV
infection.
Researchers are studying whether other factors such as multiple births and
the use of OCs work together with sexually transmitted agents (such as HPVs)
in the development of cervical cancer. Findings from an analysis of 10 studies
suggested that long-term use of OCs may increase the risk of cervical cancer
by up to 4 times in women who are infected with HPV.
However, in another long-term study published in 2002, researchers concluded
that OC use did not increase the risk of cervical cancer in a well-screened
population. The researchers followed a group of HPV-diagnosed women for 10
years. The participants were asked questions about OC use (but not the duration
of use), smoking, and number of children. The results showed that HPV-diagnosed
women who used OCs did not have a higher risk of cervical cancer than women
who did not use OCs.
More research is needed into the exact nature of the association between
OC use and risk of cervical cancer. One reason the association is unclear
is that the major risk factor for cervical cancer (history of genital HPV
infection) is related to sexual behavior. Because sexual behavior may be
different between women who use OCs and those who have never used them, it
is difficult for researchers to determine the exact role that OCs may play
in the development of cervical cancer.
Liver Tumors
There is some evidence that OCs may increase the risk of certain malignant
(cancerous) liver tumors. However, the risk is difficult to evaluate because
of different patterns of OC use and because these tumors are rare in American
women (the incidence is approximately 2 cases per 100,000 women). A benign
(noncancerous) tumor of the liver called hepatic adenoma has also been found
to occur, although rarely, among OC users. These tumors do not spread, but
they may rupture and cause internal bleeding.
Reducing Risks Through Screening
Studies have found that breast cancer screening with mammograms reduces
the number of deaths from breast cancer for women ages 40 to 69. Women who
are at increased risk for breast cancer should seek medical advice about
when to begin having mammograms and how often to be screened. A high-quality
mammogram, with a clinical breast exam (an exam done by a professional health
care provider), is the most effective way to detect breast cancer early.
Abnormal changes in the cervix can often be detected by a Pap test and treated
before cancer develops. Women who have begun to have sexual intercourse or
are age 21 should check with their doctor about having a Pap test.
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Fact Sheet: Risk of Ectopic Pregnancy after Tubal Sterilization
Among 10,685 women studied, the risk of ectopic pregnancy within 10 years
after sterilization was about 7 per 1,000 procedures. The likelihood of an
ectopic pregnancy varied according to the method of sterilization and the
age at which the women underwent the sterilization procedures.
- Ectopic pregnancy, also known as a tubal pregnancy, is a potentially
life-threatening form of pregnancy in which implantation of the fertilized
egg occurs outside the uterus.
- Among 10,685 women studied, the risk of ectopic pregnancy within 10 years
after sterilization was about 7 per 1,000 procedures.
- The purpose of this 14-year study, which was supported by the National
Institute of Child Health and Human Development at the National Institutes
of Health, was to assess the risk of ectopic pregnancy in women who have
undergone tubal sterilization.
- Ectopic pregnancy may occur long after sterilization. Ectopic pregnancy
after tubal sterilization is not rare, particularly among women sterilized
before age 30.
- Those who provide care to women of childbearing age should not assume
that a history of tubal sterilization rules out the possibility of an ectopic
pregnancy in a woman who has symptoms or signs of pregnancy, especially
ectopic pregnancy.
- The study also found that the likelihood of an ectopic pregnancy varied
according to the method of sterilization and the age at which the women
underwent the sterilization procedure. Women who were under age 30 at the
time of the procedure were twice as likely to have a subsequent ectopic
pregnancy as older women. Further, the researchers found that ectopic pregnancy
may occur many years after tubal sterilization.
- Tubal sterilization is an increasingly common method of contraception
in the United States, and even though pregnancy after sterilization is
uncommon, it can occur, and it may be ectopic.
- Women who think that they might be pregnant after sterilization should
check with their health care providers, even if the sterilization was performed
many years earlier.
- Approximately 100,000 ectopic pregnancies occur each year, and relatively
few are caused by sterilization. Often the actual cause is unknown, but
many cases result from tubal damage incurred from sexually transmitted
infections. Ectopic pregnancies are the leading cause of pregnancy-related
deaths in the first trimester and account for 9% of all pregnancy-related
deaths in this country.
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Some studies have raised questions about a possible relationship between
vasectomy (an operation to cut or tie off the two tubes that carry sperm
out of the testicles) and the risk of developing cancer, particularly prostate
and testicular cancer. Such a relationship, if proven, would be of importance
because about 1 in 6 men over age 35 in the United States has had a vasectomy.
Prostate cancer is the most common cancer in American men and the second
leading cause of cancer death in American men, after lung cancer. In March
1993, the National Institute of Child Health and Human Development (NICHD)
convened a conference, cosponsored by the National Cancer Institute (NCI)
and the National Institute of Diabetes and Digestive and Kidney Diseases,
to clarify the available evidence on the relationship between vasectomy and
prostate cancer. Scientists reviewed and carefully weighed all of the data
available at that time, including results from published and unpublished
studies.
They determined that the results of research on the association between
vasectomy and prostate cancer were not consistent. In addition, the scientists
could not find any convincing biological explanation for a link between vasectomy
and an increased risk of prostate cancer. Based on these findings, the expert
panel concluded that even if having a vasectomy can increase a man’s risk
of developing prostate cancer, the increase in risk is relatively small.
In 1997, the NCI convened the prostate cancer Progress Review Group (PRG),
a committee that included members from the scientific, medical, industrial,
and advocacy communities. This group was charged with developing a national
plan to outline scientific efforts involving prostate cancer research. The
PRG’s final report, published in August 1998, concluded that the evidence
supporting a role for vasectomy in the development of prostate cancer is
weak.
Researchers continue to investigate the possible relationship between vasectomy
and prostate cancer. The majority of studies conducted thus far have upheld
the conclusions made at the 1993 NICHD conference. Although a few studies
have reported a link between vasectomy and prostate cancer, it is possible
that other factors, including chance, may be responsible for the association
suggested in these studies.
Testicular cancer is much less common than prostate cancer, accounting for
approximately 1 percent of all cancers in American men. This type of cancer
is most often found in men ages 15 to 35. A few studies have suggested a
link between vasectomy and an increased risk of testicular cancer, but the
evidence is inconsistent and the association in some studies may be due to
factors other than vasectomy. It is also possible that the vasectomy procedure
increases the rate at which an existing, but undetected, testicular cancer
will progress. At this time, it is believed that there is either no association
or a weak association between vasectomy and testicular cancer, although more
research is needed before definitive conclusions can be reached.
Men concerned about prostate cancer or testicular cancer should talk to
their doctor about the symptoms to watch for and an appropriate schedule
for checkups.
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Vasectomy is a simple operation designed to make a man sterile, or unable to
father a child. It is used as a means of contraception in many parts of the
world. A total of about 50 million men have had a vasectomy--a number that
corresponds to roughly 5 percent of all married couples of reproductive age.
In comparison, about 15 percent of couples rely on female sterilization for
birth control.
Approximately half a million vasectomies are performed in the United States
each year. About one out of six men over age 35 has been vasectomized, the
prevalence increasing along with education and income. Among married couples
in this country, only female sterilization and oral contraception are relied
upon more often for family planning.
Vasectomy involves blocking the tubes through which sperm pass into the
semen. Sperm are produced in a man's testis and stored in an adjacent structure
known as the epididymis. During sexual climax, the sperm move from the epididymis
through a tube called the vas deferens and mix with other components of semen
to form the ejaculate. All vasectomy techniques involve cutting or otherwise
blocking both the left and right vas deferens, so the man's ejaculate will
no longer contain sperm, and he will not be able to make a woman pregnant.
In the conventional approach, a physician makes one or two small incisions,
or cuts, in the skin of the scrotum, which has been number with a local anesthetic.
The vas is cut, and a small piece may be removed. Next, the doctor ties the
cut ends and sews up the scrotal incision. The entire procedure is then repeated
on the other side.
An improved method, devised by a Chinese surgeon, has been widely used in
China since 1974. This so-called nonsurgical or no-scalpel vasectomy was
introduced into the United States in 1988, and many doctors are now using
the technique here..
In a no-scalpel vasectomy, the doctor feels for the vas under the skin of
the scrotum and holds it in place with a small clamp. Then a special instrument
is used to make a tiny puncture in the skin and stretch the opening so the
vas can be cut and tied. This approach produces very little bleeding, and
no stitches are needed to close the punctures, which heal quickly by themselves.
The newer method also produces less pain and fewer complications than conventional
vasectomy.
Regardless of how it is performed, vasectomy offers many advantages as a
method of birth control. Like female sterilization, it is a highly effective
one-time procedure that provides permanent contraception. But vasectomy is
medically much simpler than female sterilization, has a lower incidence of
complications, and is much less expensive.
After vasectomy, the patient will probably feel sore for a few days, and
he should rest for at least 1 day. However, he can expect to recover completely
in less than a week. Many men have the procedure on a Friday and return to
work on Monday. Although complications such as swelling, bruising, inflammation,
and infection may occur, they are relatively uncommon and almost never serious.
Nevertheless, men who develop these symptoms at any time should inform their
physician.
A man can resume sexual activity within a few days after vasectomy, but
precautions should be taken against pregnancy until a test shows that his
semen is free of sperm. Generally, this test is performed after the patient
has had 10-20 post-vasectomy ejaculations. If sperm are still present in
the semen, the patient is told to return later for a repeat test.
A major study of vasectomy side effects occurring within 8 to 10 years after
the procedure was published in the British Medical Journal in 1992. This
study--the Health Status of American Men, or HSAM--was sponsored by the National
Institute of Child Health and Human Development (NICHD). Investigators questioned
10,590 vasectomized men, and an equal number of nonvasectomized men, to see
if they had developed any of 99 different disorders. After a total of 182,000
person-years of follow-up, only one condition, epididymitis/orchitis (defined
as painful, swollen, and tender epididymis or testis)--was found to be more
common after vasectomy. This local inflammation most often occurs during
the first year after surgery. Treated with heat, it usually clears up within
a week.
The chief advantage of vasectomy--its permanence--is also its chief disadvantage.
The procedure itself is simple, but reversing it is difficult, expensive,
and often unsuccessful. Researchers are studying new methods of blocking
the vas that may produce less tissue damage and scarring and might thus permit
more successful reversal. But these methods are all experimental, and their
effectiveness has not yet been confirmed. It is possible to store semen in
a sperm bank to preserve the possibility of producing a pregnancy at some
future date. However, doing this is costly, and the sperm in stored semen
do not always remain viable (able to cause pregnancy). For all of these reasons,
doctors advise that vasectomy be undertaken only by men who are prepared
to accept the fact that they will no longer be able to father a child. The
decision should be considered along with other contraceptive options and
discussed with a professional counselor. Men who are married or in a serious
relationship should also discuss the issue with their partners.
Although it is extremely effective for preventing pregnancy, vasectomy does
not offer protection against AIDS or other sexually transmitted diseases.
Consequently, it is important that vasectomized men continue to use condoms,
preferably latex, which offer considerable protection against the spread
of disease, in any sexual encounter that carries the risk of contracting
or transmitting infection.
Vasectomy does not affect production or release of testosterone, the male
hormone responsible for a man's sex drive, beard, deep voice, and other masculine
traits. The operation also has no effect on sexuality. Erections, climaxes,
and the amount of ejaculate remain the same.
Occasionally, a man may experience sexual difficulties after vasectomy,
but these almost always have an emotional basis and can usually be alleviated
with counseling. More often, men who have undergone the procedure, and their
partners, find that sex is more spontaneous and enjoyable once they are freed
from concerns about contraception and accidental pregnancy.
After vasectomy, the testes continue to make sperm. When the sperm cells
die, they are absorbed by the body, much like unused sperm in a nonvasectomized
man. Nevertheless, many vasectomized men develop immune reactions to sperm,
although current evidence indicates that these reactions do not cause any
harm.
Ordinarily, sperm do not come in contact with immune cells, so they do not
elicit an immune response. But vasectomy breaches the barriers that separate
immune cells from sperm, and many men develop anti-sperm antibodies after
undergoing the procedure. This has given rise to concern on the part of doctors
and researchers, because immune reactions against parts of one's own body
sometimes cause disease. Rheumatoid arthritis, juvenile diabetes, and multiple
sclerosis are just some of the illnesses suspected or known to be caused
by immune reactions of this type.
Immune reactions can also contribute to the development of atherosclerosis,
the clogging of arteries that leads to heart attacks. In the late 1970s,
after a study of 10 monkeys showed an increased risk of atherosclerosis in
vasectomized animals, doctors became concerned that vasectomy might increase
the risk of heart disease in men.
Other, more persuasive research results, however, indicated that these concerns
were not warranted. In particular, the HSAM study provided a high level of
reassurance. Researchers conducting this study found no evidence that vasectomized
men were more likely than others to develop heart disease or any other immune
illnesses.
But just as concerns about heart disease and immune ailments following vasectomy
were being laid to rest, worries about prostate cancer were taking their
place.
Although the HSAM and a number of other studies showed no increase in cancer
among vasectomized men, three separate hospital-based studies published in
1990 reported positive correlations between vasectomy and prostate cancer.
However, a well-regarded 1991 study found no such relationship.
Because of the importance of the issue, all of this research has been carefully
analyzed, and scientists have identified several potential problems in the
studies. It is possible, for example, that men who choose vasectomy for contraception
have above average access to health care. In particular, these men may be
more likely than others to visit urologists--physicians whose specialty includes
the male reproductive organs, and they might thus be more likely to receive
an accurate diagnosis of prostate cancer, a disease that often causes no
symptoms and remains undiagnosed. If this were the case, vasectomy might
falsely appear to increase the risk of this cancer.
In October 1991, the World Health Organization (WHO) sponsored a meeting
of experts from around the world to evaluate the available evidence regarding
a link between vasectomy and prostate cancer. Because additional concerns
had been raised about a possible association between vasectomy and testicular
cancer, evidence for such an association was also weighed at the meeting.
The assembled experts concluded that a causal relationship between vasectomy
and cancer of either the prostate or testis was unlikely. This conclusion
was based in large measure on an overview of study results. But it was strengthened
by the absence of a biological explanation of how vasectomy might product
any form of cancer.
Following the WHO meeting, two additional studies of vasectomized men found
no increased risk of either prostate cancer or all cancers combined. Subsequently,
a study conducted in three regions of the United States suggested that the
subgroup of men who had a vasectomy before age 35 might have a slightly increased
risk of developing prostate cancer. However, the size of this subgroup was
not large enough to make the result conclusive. The study did not find any
increased cancer risk in men who underwent vasectomy after age 35.
In 1993, a noted team of Harvard epidemiologists published findings from
two large studies in the Journal of the American Medical Association (JAMA).
One of these studies was retrospective (backward-looking), while the other
was prospective and followed new patients. Both found vasectomy to be associated
with a moderately elevated relative risk of prostate cancer that increased
with time after the procedure. After more than 20 years, a vasectomized man
appeared to be twice as likely to develop prostate cancer as a nonvasectomized
man of the same age. Although this conclusion may seem startling, scientists
generally consider risk findings of this magnitude to be of doubtful significance.
The studies were examined by experts in several professional organizations
as well as in a JAMA article. The authors of this article concluded that
the studies could neither be relied upon nor ignored and that further research
was essential.
These authors pointed out that, since the causes of prostate cancer remain
unknown, it had been impossible to assure that risk factors for the illness
were equally distributed between the vasectomized and nonvasectomized men.
In one of the studies, the men who had undergone vasectomy had a lower overall
death rate than the men who had not, supporting the likelihood that the two
groups had different characteristics. Differences of this type might have
affected prostate cancer risk, producing study results that misleadingly
implicated vasectomy as a cause of prostate cancer.
Like others before them, these scientists also noted the lack of evidence
for any biological mechanism that could link vasectomy with prostate cancer.
In 1993, NICHD convened a meeting at which an expert panel considered published
data, preliminary results from studies in progress, and an analysis of eight
epidemiologic studies, including the two reports mentioned above. The panelists
concluded that the positive associations between vasectomy and prostate cancer
found in some studies might or might not be valid. Scientists agree, however,
that if any increased risk is caused by vasectomy, it is relatively small.
WHO is currently conducting a major study of vasectomy and prostate cancer
in several developing countries, and three other studies are ongoing in the
United States and Canada. Scientists expect these investigations to help
resolve the issue.
In the interim, most physicians will be guided by NICHD's expert panel of
1993 which concluded there is insufficient basis for recommending any change
in current clinical or public health practice. Providers should continue
to offer vasectomy and to perform the procedure, the panel said. Vasectomy
reversal is not warranted to prevent prostate cancer, and screening for prostate
cancer should not be any different for men who have had a vasectomy than
for those who have not undergone the procedure.
Vasectomy has been used for about a century as a means of sterilization.
It has a long track record as a safe and effective method of contraception
and is relied upon by millions of people throughout the world. On the basis
of much evidence, experts believe that vasectomy can safely continue to be
used as it has been in the past, while further research is carried out.
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