Genital tract infection and pelvic surgery contribute to the development of endometriosis.

Endometriosis is a multifactorial disease, and inflammation is considered a core pathology. Inflammation related to genital tract infection (GTI) and surgical injury may cause endometriosis. Therefore, we investigated the incidence of endometriosis in women with a recent history of GTI, pelvic surgery, or both. Using the Korean National Health Insurance Service-National Sample Cohort, 20- to 49-year-old women diagnosed with GTI or who underwent pelvic surgeries between 2002 and 2008 were collected and followed up for five years. After excluding women who had already been diagnosed with endometriosis or diseases that may affect endometriosis, a total of 30,336 women were diagnosed with GTI (Study 1), 2894 women who underwent pelvic surgery (Study 2), and 788 women who underwent GTI and pelvic surgery, both (Study 3) were enrolled for each study. The comparison groups in which sociodemographic factors matched for each group were collected. The incidence of endometriosis per 1000 person-year was 5.37, 5.17, and 20.81 in each case group and was significantly higher than each comparison group. A recent history of GTI increased an adjusted hazard ratio (aHR) of 2.29 (1.99-2.63, 95% confidence interval) for the development of endometriosis. The aHRs of pelvic surgery history and the history of both GTI and pelvic surgery were 2.10 and 7.82, respectively. In conclusion, the pelvic inflammation resulting from genital infection and pelvic surgical injury may play a role in developing endometriosis. Active treatment of genital infections and careful surgical procedures to minimize tissue injury may reduce the incidence of pelvic endometriosis.