Prevalence of and risk factors for chronic endometritis in patients with intrauterine disorders after hysteroscopic surgery

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Keiji Kuroda, M.D., Ph.D., Akina Yamanaka, M.D., Satoru Takamizawa, M.D., Ph.D., Kazuki Nakao, M.D., Yasushi Kuribayashi, M.D., Ph.D., Koji Nakagawa, M.D., Ph.D., Shuko Nojiri, Ph.D., Hirotaka Nishi, M.D., Ph.D., Rikikazu Sugiyama, M.D., Ph.D.



To identify the prevalence of and risk factors for chronic endometritis (CE) in patients with intrauterine disorders and the therapeutic efficacy of hysteroscopic surgery in the treatment of CE without antibiotic therapy.


Prospective cohort study.


Hospital specializing in reproductive medicine.


The study population consisted of 350 women with infertility, of whom 337 were recruited, who underwent hysteroscopic surgery between November 2018 and June 2021. Eighty-nine consecutive patients without intrauterine disorders were also recruited as controls.


Endometrial samples were collected during the surgery for CD138 immunostaining for the diagnosis of CE. In women diagnosed with CE, endometrial biopsy was performed without antibiotic use in the subsequent menstrual cycle.

Main Outcome Measure(s)

Prevalence of and risk factors for CE in intrauterine disorders and therapeutic effects of hysteroscopic surgery on CE.


The prevalence of CE with ≥5 CD138-positive cells in women with no intrauterine disorder and with endometrial polyps, myomas, intrauterine adhesions (IUAs), and septate uterus was 15.7%, 85.7%, 69.0%, 78.9%, and 46.2%, respectively. A multivariate analysis revealed that CE was diagnosed significantly more often in the endometrial polyp (odds ratio, 27.69; 95% confidence interval, 15.01–51.08) and IUA groups (odds ratio, 8.85; 95% confidence interval, 3.26–24.05). The rate of recovery from CE with surgery in women with endometrial polyps, myomas, IUA, and septate uterus was 89.7%, 100%, 92.8%, and 83.3%, respectively.


Endometrial polyp and IUA were risk factors for CE. Most CE cases with intrauterine disorders were cured with hysteroscopic surgery without antibiotic therapy, regardless of the type of intrauterine abnormalities.