Extent of surgery for pelvic inflammatory disease in relation to duration of intrauterine device use.

The risk of a first episode of pelvic inflammatory disease resulting in extensive surgery was examined in relation to duration of intrauterine device (IUD) use in a case-control study. Extensive surgery for pelvic inflammatory disease was defined as hysterectomy or bilateral adenexal surgery, with pelvic inflammatory disease as the only gynecologic discharge diagnosis. Of 690 hospitalized pelvic inflammatory disease patients with no prior history of the disease, 55 had extensive (requiring surgery) disease. These were compared to 2569 controls who were hospitalized with nongynecologic conditions. Current IUD users (within 30 days of admission) were considered to be long-term or short-term users, depending upon whether the same IUD had been used for five or more years or less than five years. Past IUD users and never-users were considered to be nonusers. For long-term users as compared to nonusers, the relative risk of extensive pelvic inflammatory disease was about 5.4; for short-term users as compared to nonusers, the relative risk was only about 1.4. Continuous use of the same IUD for five or more years appears to increase the risk of pelvic inflammatory disease, requiring extensive surgery to a greater extent than use for less than five years.