Definition of Pelvic inflammatory disease (PID):

Pelvic inflammatory disease is a general term for infection of the lining of the uterus, the fallopian tubes, or the ovaries.

See also: Endometritis

Causes, incidence, and risk factors:

The majority of pelvic inflammatory disease cases are caused by the same bacteria that lead to sexually transmitted diseases (such as chlamydia, gonorrhea, mycoplasma, staph, strep).

Although the cause of PID most commonly spreads through sex, bacteria may also enter the body after gynecological procedures such as the insertion of an intrauterine device (IUD), childbirth, miscarriage, therapeutic or elective abortion, and endometrial biopsy.

In the United States, nearly 1 million women develop PID each year. It is estimated that 1 in 8 sexually active adolescent girls will develop PID before reaching age 20. Since PID is frequently underdiagnosed, statistics are probably greatly underestimated.

Risk factors include:

• Sexual activity during adolescence
• Multiple sexual partners
• Past history of PID
• Past history of any sexually transmitted disease
• Insertion of an IUD

Birth control pills are thought in some cases to lead to cervical ectropion, a condition that allows easier access to tissue where bacteria may grow. However, birth control pills may protect against PID by stimulating the body to produce a thicker cervical mucous, which makes it harder for semen to carry bacteria to the uterus.