Reproductive History and Clinical Symptom-Related Risk Factors for Chronic Endometritis in Infertile Women: A Retrospective Case-Control Study.

Aims/Background The diagnosis of chronic endometritis (CE) in infertile women without demonstrable intrauterine abnormalities remains a significant clinical challenge. The primary aim of this study was to identify the independent risk factors for CE regarding reproductive history and clinical symptoms in infertile women, providing evidence-based guidance for targeted CE screening in this population. Methods In this retrospective case-control study, a total of 180 infertile female patients undergoing hysteroscopy between October 2022 and July 2024, who fulfilled the enrollment criteria, were included. The participants were divided into two groups: non-chronic endometritis (NCE) group (n = 78) and CE group (n = 102). CE was diagnosed based on the syndecan-1 (CD138) immunohistochemical staining results. To evaluate the association of CE with reproductive history and clinical symptoms, both univariate and multivariate logistic regression analyses were conducted. Results The prevalence of CE in this study was 56.67% (102/180). Univariate logistic regression analysis revealed statistically significant differences in gravidity, parity, abortion history, and prolonged menstruation between the two groups (p < 0.05), indicating their correlations with CE. Further multivariate analysis identified abortion history (odds ratio [OR] = 2.521, 95% confidence interval [CI]: 1.307-4.864, p = 0.006) and prolonged menstruation (OR = 3.624, 95% CI: 1.141-11.513, p = 0.029) as independent risk factors for CE, while gravidity and parity showed no significant associations after adjustment. Conclusion Abortion history and prolonged menstruation are independent risk factors for CE. For infertile women presenting with a history of abortion or prolonged menstruation but without apparent intrauterine abnormalities, hysteroscopy combined with CD138 immunohistochemical staining is recommended to facilitate early diagnosis and prompt therapeutic intervention for CE.