Pelvic Inflammatory Disease
Aside from AIDS, the most common and serious complication of sexually transmitted diseases
(STDs) among women is pelvic inflammatory disease (PID), an infection of the upper genital tract.
PID can affect the uterus, ovaries, fallopian tubes, or other related structures. Untreated, PID
causes scarring and can lead to infertility, tubal pregnancy, chronic pelvic pain, and other serious
Each year in the United States, more than 1 million women experience an episode of acute PID,
with the rate of infection highest among teenagers. More than 100,000 women become infertile
each year as a result of PID, and a large proportion of the 70,000 ectopic (tubal) pregnancies
occurring every year are due to the consequences of PID. In 1997 alone, an estimated $7 billion
was spent on PID and its complications.
PID occurs when disease-causing organisms migrate upward from the urethra and
cervix into the upper genital tract. Many different organisms can cause PID, but most
cases are associated with gonorrhea and genital chlamydial infections, two very
common STDs. Scientists have found that bacteria normally present in small numbers
in the vagina and cervix also may play a role.
Investigators are learning more about how these organisms cause PID. The
gonococcus, Neisseria gonorrhea, probably travels to the fallopian tubes, where it
causes sloughing (casting out) of some cells and invades others. Researchers think it
multiplies within and beneath these cells. The infection then may spread to other
organs, resulting in more inflammation and scarring.
Chlamydia trachomatis and other bacteria may behave in a similar manner.
Researchers do not know how other bacteria that normally inhabit the vagina (e.g.,
organisms such as Gardnerella vaginalis and Bacteroides) gain entrance into the
upper genital tract. The cervical mucus plug and secretions may help prevent the
spread of microorganisms to the upper genital tract, but it may be less effective during
ovulation and menses. In addition, the gonococcus may gain access more easily during
menses, if menstrual blood flows backward from the uterus into the fallopian tubes,
carrying the organisms with it. This may explain why symptoms of PID caused by
gonorrhea often begin immediately after menstruation as opposed to any other time
during the menstrual cycle. It is noteworthy that the co-incidence of menses and
chlamydial infection is not a prominent feature of chlamydial PID.
The major symptoms of PID are lower abdominal pain and abnormal vaginal discharge.
Other symptoms such as fever, pain in the right upper abdomen, painful intercourse,
and irregular menstrual bleeding can occur as well. PID, particularly when caused by
chlamydial infection, may produce only minor symptoms or no symptoms at all, even
though it can seriously damage the reproductive organs.
Risk Factors for PID
Women with STDs – especially gonorrhea and chlamydial infection – are at
greater risk of developing PID; a prior episode of PID increases the risk of
another episode because the body’s defenses are often damaged during the
initial bout of upper genital tract infection.
Sexually active teenagers are more likely to develop PID than are older women.
The more sexual partners a woman has, the greater her risk of developing PID.
Recent data indicate that women who douche once or twice a month may be more
likely to have PID than those who douche less than once a month. Douching may push
bacteria into the upper genital tract. Douching also may ease discharge caused by an
infection, so the woman delays seeking health care.
PID can be difficult to diagnose. If symptoms such as lower abdominal pain are
present, the doctor will perform a physical exam to determine the nature and location of
the pain. The doctor also should check the patient for fever, abnormal vaginal or
cervical discharge, and evidence of cervical chlamydial infection or gonorrhea. If the
findings of this exam suggest that PID is likely, current guidelines advise doctors to
If more information is necessary, the doctor may order other tests, such as a sonogram,
endometrial biopsy, or laparoscopy to distinguish between PID and other serious
problems that may mimic PID. Laparoscopy is a surgical procedure in which a tiny,
flexible tube with a lighted end is inserted through a small incision just below the navel.
This procedure allows the doctor to view the internal abdominal and pelvic organs, as
well as take specimens for cultures or microscopic studies, if necessary.
Because culture of specimens from the upper genital tract are difficult to obtain and
because multiple organisms may be responsible for an episode of PID, especially if it
is not the first one, the doctor will prescribe at least two antibiotics that are effective
against a wide range of infectious agents. The symptoms may go away before the
infection is cured. Even if symptoms do go away, patients should finish taking all of the
medicine. Patients should be re-evaluated by their physicians two to three days after
treatment is begun to be sure the antibiotics are working to cure the infection.
About one-fourth of women with suspected PID must be hospitalized. The doctor may
recommend this if the patient is severely ill; if she cannot take oral medication and
needs intravenous antibiotics; if she is pregnant or is an adolescent; if the diagnosis is
uncertain and may include an abdominal emergency such as appendicitis; or if she is
infected with HIV (human immunodeficiency virus, the virus that causes AIDS).
Many women with PID have sex partners who have no symptoms, although their sex
partners may be infected with organisms that can cause PID. Because of the risk of
reinfection, however, sex partners should be treated even if they do not have symptoms.
Consequences of PID
Women with recurrent episodes of PID are more likely than women with a single
episode to suffer scarring of the tubes that leads to infertility, tubal pregnancy, or
chronic pelvic pain. Infertility occurs in approximately 20 percent of women who have
Most women with tubal infertility, however, never have had symptoms of PID.
Organisms such as C. trachomatis can silently invade the fallopian tubes and cause
scarring, which blocks the normal passage of eggs into the uterus.
A women who has had PID has a six-to-tenfold increased risk of tubal pregnancy, in
which the egg can become fertilized but cannot pass into the uterus to grow. Instead,
the egg usually attaches in the fallopian tube, which connects the ovary to the uterus.
The fertilized egg cannot grow normally in the fallopian tube. This type of pregnancy is
life-threatening to the mother, and almost always fatal to her fetus. It is the leading
cause of pregnancy-related death in African-American women.
In addition, untreated PID can cause chronic pelvic pain and scarring in about 20
percent of patients. These conditions are difficult to treat but are sometimes improved
Another complication of PID is the risk of repeated attacks of PID. As many as
one-third of women who have had PID will have the disease at least one more time.
With each episode of reinfection, the risk of infertility is increased.
Women can play an active role in protecting themselves from PID by taking the
Signs of discharge with odor or bleeding between cycles could mean infection.
Early treatment may prevent the development of PID.
If used correctly and consistently, male latex condoms will prevent transmission of
gonorrhea and partially protect against chlamydial infection.