Establishment and verification of hysteroscopic scoring system for chronic endometritis in infertile patients.

Objectives: To establish and verify a hysteroscopic scoring system for the diagnosis of chronic endometritis (CE) in infertile patients.

Methods: A total of 238 infertile patients who underwent hysteroscopy and endometrial biopsy in the Reproductive Medicine Center, Shijiazhuang Obstetrics and Gynecology Hospital Affiliated to Hebei Medical University from October 1 to December 31, 2019 were enrolled in the study. According to the results of CD138 immunohistochemistry, the patients were divided into CE group (=73) and non-CE group (=165). Univariate and binary logistic regression analyses were used to screen the risk factors of CE and a nomogram was establish for hysteroscopic scoring. Receiver operating characteristic (ROC) curve, calibration curve and Bootstrap resampling method were used to evaluate and verify the system.

Results: Univariate and binary logistic regression analyses showed that hyperemia area (HA) degree ≥2, micropolyps, polypoid hyperplasia of endometrium and history of ectopic pregnancy were independent risk factors for CE (all <0.05). A nomogram was generated to establish a hysteroscopy scoring system based on the above four factors. The area under ROC curve of the hysteroscopy scoring system for predicting CE was 0.801 (95%:0.742-0.861), the sensitivity was 74.0% and the specificity was 73.9%. The calibration curve showed that the predicting value of the scoring system was highly consistent with the actual value. In the internal verification, the C-index was 0.7811. The predicting value of the verification group in the calibration curve was basically consistent with the actual value, indicating that the scoring system had good stability.

Conclusions: The hysteroscopic scoring system composed of HA, micropolyp, polypoid hyperplasia of endometrium and history of ectopic pregnancy can effectively and intuitively predict CE, which is conducive to improving the diagnosis of CE.