Infections and the Reproductive Microbiome · Chronic Endometritis
RRM Academy Synopsis
Chronic endometritis is common in women with unexplained infertility
Chronic endometritis, a lasting swelling of the womb lining, was reported in nearly 6 out of 10 women with unexplained infertility. This 2025 review looks at how doctors find it, how it may block a pregnancy from taking hold, and how antibiotics fared.
Key Findings
- Reported rates of chronic endometritis were 57.5% in repeated implantation failure, 56% in recurrent spontaneous abortion, and 56.8% in unexplained infertility.
- In one cited study, endometrial cultures were positive in 73.1% of 438 women with chronic endometritis and 5% of 100 women without it.
- In one cited study, Lactobacillus made up 1.89% of the endometrial bacteria in women with chronic endometritis and 80.7% in women without it.
- In one cited study of unexplained infertility, natural pregnancy occurred in 76.3% after treatment for chronic endometritis, 20% with persistent disease, and 9.5% without it.
Interpretation
The paper is a narrative review. The authors summarize published studies and report no pooled analysis. The figures come from single studies cited by the review. Tissue tests, hysteroscopy, and cultures each have limits, and no consensus exists on hysteroscopy criteria, so reported rates vary. The authors say the best antibiotic plan and follow-up timing remain unclear, and the exact ways the condition affects fertility are not fully understood.
RRM Context
Unexplained infertility means undiagnosed. Chronic endometritis is one condition that can sit behind that label. Restorative reproductive medicine looks for the cause first and treats it once found.
Abstract
Chronic endometritis (CE) is a subtle but persistent inflammatory disorder of the endometrium that is often underdiagnosed due to its asymptomatic or non-specific presentation. The etiology of CE primarily involves microbial infections and immune dysregulation, often accompanied by microbial dysbiosis. Diagnosis relies on histopathological examination, especially the identification of stromal plasma cells, alongside hysteroscopic findings and microbiological testing, though standardization remains lacking. Mechanistically, CE-induced infertility stems from altered immune cell profiles, impaired endometrial receptivity, aberrant decidualization, dysbiosis of the endometrial microbiota, and abnormal uterine peristalsis. Aberrant gene expression and hormone receptor dysregulation further disrupt the implantation window. This review summarizes current understanding of the diagnostic criteria, pathogenic mechanisms, and therapeutic strategies for CE, emphasizing its crucial role in infertility and the need for standardized clinical management.