Existence of chronic endometritis and its influence on pregnancy outcomes in infertile women with minimal/mild endometriosis

Objective This study aimed to evaluate the prevalence of chronic endometritis (CE) in women with minimal/mild endometriosis and to analyze whether CE affects their pregnancy outcomes. Methods This retrospective study included 201 infertile women who were diagnosed with minimal/mild endometriosis after undergoing hysteroscopy combined with laparoscopy from January 2016 to December 2018. Immunohistochemistry was used to detect CD138 and CD38, which are specific markers of plasma cells in the endometrial stroma to diagnose CE. Subsequently, we investigated the prevalence of CE and the effects of CE on spontaneous cumulative pregnancy rate, live birth rate, and miscarriage rate within 24 months after surgery. Results The prevalence of CE in infertile women with minimal/mild endometriosis was 24.38%. Patients diagnosed with CE showed a significantly lower cumulative pregnancy rate and live birth rate compared with women without CE (46.51% vs. 71.13% [P = 0.004]; 44.19% vs. 63.38% [P = 0.025]). However, the rate of miscarriage in women with CE was also lower than in women without CE (0 vs. 7.04%, P = 0.074). Conclusion Since CE had an adverse effect on cumulative pregnancy rate and live birth rate in infertile women with minimal/mild endometriosis, we suggested that diagnosis and treatment of CE may improve their pregnancy outcomes.