A retrospective analysis of chronic endometritis and antibiotic therapy in patients with endometriosis

Chronic endometritis is linked to recurrent pregnancy loss and in vitro fertilization failure. The responsiveness to antibiotics suggests a bacterial cause, however endometriosis could also play a role. This study aimed to compare treatment responses to antibiotics of patients with and without endometriosis to find out if endometriosis-related immune changes affect treatment success. We included 92 infertile women with chronic endometritis in the study. Endometriosis was staged via laparoscopy according to the revised American Society for Reproductive Medicine, adenomyosis was defined using transvaginal ultrasound. All patients were reassessed via Pipelle® after oral doxycycline treatment. The main outcome parameter was the number of CD138 positive plasma cells per 20 high-power fields before and after doxycycline. In the univariable analysis, the presence of endometriosis (odds ratio, OR 2.893; p = 0.026) and adenomyosis (OR 10.277; p < 0.001) was associated with a higher risk of persistent chronic endometritis after doxycycline, whereas in the multivariable model, the presence of adenomyosis (OR, 18.393; p < 0.001) and the baseline number of plasma cells (OR 1.371; p = 0.026) remained statistically significant. Endometriosis and adenomyosis are risks for persistent chronic endometritis after doxycycline treatment. This could support the hypothesis that affected women could have heterogeneous endometrial immunological processes.