What Causes Pelvic Inflammatory Disease?

There are several important factors that causesPelvic Inflammatory Disease (PID):

  1. First is exposure to an infected partner.
  2. Second is exposure to infection immediately prior to menstruation. Menstrual blood provides an excellent growth medium for bacteria, promoting their proliferation and passage via the uterine cavity into the fallopian tubes.
  3. Third is relative ill health and poor nutritional status. It is predominantly for this reason that Pelvic Inflammatory Disease runs a rampant course in lower socioeconomic groups.
  4. Fourth is the fact that previously infected tissues are highly susceptible to re-infection; resulting in women with a past history of Pelvic Inflammatory Disease being highly susceptible to recurrent attacks.

While sexually transmitted Pelvic Inflammatory Disease is certainly capable of causing endometritis (infection of the uterine lining) the uterus itself is not the main focus of the inflammatory process. Cyclical shedding of most of the uterine lining with menstruation tends to remove infected tissue monthly, thereby preventing the inflammation from taking a hold and causing permanent damage to or scarring of the uterine lining (the endometrium). The main site of inflammation following sexual transmitted PID is the fallopian tube via which other pelvic and abdominal structures may be infected.

In contrast, pelvic inflammatory disease that occurs following childbirth or abortion primarily targets the uterine lining, causing endometritis. Organisms such as Bacteroides, Peptostreptococcus, Beta hemolytic streptococcus, and E. Coli readily proliferate in the products of conception that are sometimes retained in the uterus following childbirth and abortion. The delayed onset of menstruation after both childbirth and abortion provides an opportunity for the inflammatory process to take hold and progress, sometimes leading to the development of scar tissue in the uterine cavity. This may cause opposing surfaces of the endometrium to fuse together or produce scarring which obliterates the opening (in the uterus) into the fallopian tubes and might also damage a small, adjacent segment of the tubes.

Less commonly, post-childbirth and post-abortalendometritis infects the entire fallopian tube(s) (salpingitis) as well as causing partial or complete blockage, and/or spreading into the pelvic cavity.

Pelvic Inflammatory Disease (PID) may also result from the use of the Intrauterine Contraceptive device (IUD) for contraceptive purposes. This most commonly occurs in cases where the device is inserted into the uterus of women concurrently infected with Gonorrhea or Chlamydia. The IUD acts as a foreign body causing local irritation which compromises the normal defense mechanisms that normally protect against infection. At the same time, the IUD string which protrudes through the cervix into the vagina may act as a “wick” via which infecting organisms gain entrance to the uterus. As with post-abortal and post-childbirth endometritis, IUD-related uterine infection often causes scarring of the endometrial lining, utero-cornual occlusion (this is where the fallopian tube(s) leave the uterine wall), salpingitis, and inflammation of other pelvic structures. IUD-related PID is a potentially life endangering condition capable of causing pelvic abscess formation, the development of peritonitis (inflammation of the peritoneum), systemic infection (septicemia), and shock.