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
- 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
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 begin treatment.
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
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 had PID.
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 with surgery.
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.
Note: All information is based upon materials published by the National
Institute of Allergy and Infectious Diseases (NIAD) and the
U. S. Centers for Disease Control.