Pelvic Inflammatory Disease (PID)

Pelvic inflammatory disease, or PID, is an inflammation of a woman's upper reproductive tract. Affected areas can include the structures of the uterus, ovaries, and fallopian tubes. Salpingitis, inflammation of the fallopian tubes, is the most common manifestation of the disease. PID is known to be a long-term consequence of many sexually transmitted diseases as well as of bacterial vaginosis (BV), pelvic surgery, and other gynecologic procedures that cross the cervix. It is fundamentally a preventable condition. It is also a leading cause of preventable infertility. 

Pelvic inflammatory disease is, essentially, caused by the body overreacting to an infection. As the immune system tries to fight off the invading bacteria, it causes local inflammation and scarring. Although this may successfully wall off the infection inside the reproductive tract, it can be damage the organs. PID can cause scarring in the uterus, fallopian tubes, and even in the pelvic cavity. This is one of the main reasons it causes chronic pelvic pain.

The most common infections associated with pelvic inflammatory disease are chlamydia and gonorrhea. Because the symptoms of PID are the result of the body's response to the underlying infection, treatment usually involves antibiotics to treat that infection. In severe cases, or in an emergency, surgery may be necessary to drain an abscess that has ruptured or that threatens to rupture.

• Pain in the lower abdomen and pelvis
• Irregular periods
• Pain during sex
• Pain during urination
• Lower back pain
• Excess vaginal discharge with a foul odor
• Fever, exhaustion, diarrhea, vomiting, and other general signs of infection.

In the early 1990s, the self-reported frequency of PID in women was approximately one in nine. PID was more than twice as common in women with a history of sexually transmitted diseases (26 percent) than among women who had never reported an STD (10 percent). Fortunately, PID has become less common as screening for chlamydia and gonorrhea has become more widespread. 

Risk factors for PID include:

• Younger age: Sexually experienced teenagers are three times more likely to be diagnosed with PID than their 25- to 29-year-old counterparts. Scientists do not know, however, why this is the case. It may be due to biological factors that make young women more susceptible to STDs. It could also reflect different sexual behaviors in these two age groups.
• Race: African-American women have the highest risk of PID of the ethnic groups seen in the U.S. This may be related to biological factors. It could also be related to their comparatively high frequency of douching.
• Contraceptive Choice: Barrier methods, such as condoms, and oral contraceptives reduce the risk of PID. Despite the problems with the Dalkon Shield in the 1970s, use of modern intrauterine devices (IUD) is not considered to significantly increase the risk of PID, except possibly around the time of insertion.
• Douching: Douching greatly increases a woman's risk of PID.

Worldwide, PID is one of the leading causes of ectopic pregnancy and preventable infertility in women. In 2000, a study estimated that the cost of PID in the US was in the vicinity of $2 billion. An earlier study that examined the costs of preventable infertility found that the costs were closer to $64 billion. That study included the cost of both treating the  STDs and PID that caused the infertility, and resolving the infertility in couples who wished to become pregnant.

In contrast to the costs of treating PID infertility, the costs of preventing PID-related infertility are probably much lower. Those costs would primarily include those for education about safer sex, douching, and condom use as well as screening and treatment for chlamydia and other STDs. The cost of such preventative measures would probably be only a minuscule fraction of the cost spent on treatment.

The relationship between PID and infertility is relatively well accepted. PID causes infertility by the scarring process that occurs during the healing of sexually transmitted infections. The extensive scarring can eventually occlude one or both fallopian tubes. Scarring tends to be worse among older women, smokers and women using IUDs. Depending on the extent of scarring it may be impossible for sperm to reach the egg, or, if sperm can get through, the fertilized egg may be unable to get to the uterus. If a fertilized egg can not get to the uterus, it may become an ectopic pregnancy. 

Not surprisingly, the percentage of women who experience infertility due to PID is directly proportional to the number of episodes of PID that they have experienced. Therefore, both treating and preventing PID are important steps in the reduction of infertility in the United States.