Chronic Endometritis Research Articles

P-319 Chronic endometritis prevalence, associated factors and pregnancy outcome among infertile women

Abstract Study question What are the prevalence, associated factors and pregnancy outcome of chronic endometritis(CE) among infertile women? Summary answer The overal prevalence of chronic endometritis in infertile women was 24.7%. Diagnosis rate of CE was higher in primary infertility compared to other infertility groups. What is known already Chronic endometritis is defined as a chronic inflammation of uterine endometrium. The prevalence of chronic endometritis varies across different groups and diagnostic criteria. The pathophysiology of chronic endometritis remained unclear, therefore, associated factors of chronic endometritis are uncertain. Study design, size, duration We perfomed an single-center, retrospective study between May 2019 and July 2023. By doing so, we collected data on 486 infertile women. Participants/materials, setting, methods A total of 486 infertile women, who underwent hysteroscopy by single surgeon, were recruited. The diagnosis of chronic endometritis was confirmed by presence of plasma cell per section in hematoxylin-eosin stain or CD138 immunohistochemical staining. Preoperative information (including age, body mass index, smoking, alcohol consumption, clinical presentation of infertility, endometrial thickness at ovulatory phase, anti-mullerian hormone (AMH) level and infertility factors) and post-operative information (including endometrial histology and pregnancy outcome) were collected. Main results and the role of chance The prevalence of chronic endometritis in the 486 infertile women with hysteroscopy guided endometrial biopsy was 24.7%. Prevalence of chronic endometritis was 28.1%, 19%, 22.2%, 27.2% in women with primary infertility, secondary infertility, recurrent pregnancy loss (RPL) and repeated implantation failure (RIF), respectively. A multivariate analysis revealed that overweight was associated with lower risk of chronic endometritis than underweight (relative risk (RR) = 0.56, 95% confidence interval (CI): 0.32-0.98, p = 0.042). Primary infertility was associated with higher risk of chronic endometritis than non-primary infertility (RR = 1.44, 95% CI: 1.02-2.03, p = 0.039). The pregnancy rate (including spontaneous pregnancies) was comparable between women with treated chronic endometritis and without chronic endometritis; 54.7% versus 61.7% in clinical pregnancy rate and 82.8% vs 85.4% in ongoing pregnancy rate. The prevalence of chronic endometritis with coexisting endometrial lesion (endometrial polyps, submucous myoma, or both of them) was 61.7%. Limitations, reasons for caution Our retrospective study has a less powerful design compared to a prospective randomized controlled study. Wider implications of the findings In women with primary infertility, the diagnosis rate of chronic endometritis was higher compared to other infertility groups. Therefore, even in cases of primary infertility, chronic endometritis should be considered as a potential cause of infertility. Trial registration number not applicable

P-291 In women with endometriosis, effective treatment of chronic endometritis with antibiotics lowers serum CA-125 levels

Abstract Study question To evaluate the effect of chronic endometritis treatment on serum CA-125 levels in women with endometriosis. Summary answer Cure of chronic endometritis leads to a reduction in serum Ca-125 levels in women with endometriosis. What is known already Endometriosis is a chronic inflammatory disease characterized by the ectopic growth of endometrial tissue outside the uterine cavity. It is hypothesized that the disease exerts direct inflammatory effects on the ovaries, fallopian tubes, and the eutopic endometrium. In endometriosis, CA-125 levels are often elevated. Literature reports a frequent coexistence of endometriosis and chronic endometritis (CE) in women undergoing hysterectomy for benign indications. CE, characterized by macroscopic and histological alterations of the endometrium, was present in 38.5%-42.3% of women with endometriosis, compared to lower prevalence rates in controls infertile patients without endometriosis, supporting a potential etiopathogenic link between endometriosis and CE. Study design, size, duration This retrospective case-control study was conducted at the Department of Obstetrics and Gynecology, University of Bari. The study included 51 patients suffering of both ovarian endometriosis and CE. The primary objective was to investigate whether CE cure modifies serum CA-125 levels among women with ovarian endometriosis. The secondary objective was to assess any modifications in the size of endometriotic cysts following the cure of CE. Recruitment period was from September 2021 to February 2023. Participants/materials, setting, methods All patients received antibiotic therapy (100 mg of doxycycline, twice daily for ten days) and, the following month, hysteroscopy with control biopsy. Of these, 36 women were cured of chronic endometritis (Group A), while 15 women showed persistent disease (Group B). Endometriosis was diagnosed by transvaginal ultrasound and chronic endometritis through hysteroscopy, histology, and immunohistochemistry for CD138. Serum CA-125 levels were measured before antibiotic therapy and approximately 3 months later. Main results and the role of chance The primary outcome was to compare the change in CA-125 values between women cured of chronic endometritis and women with persistent disease. There were no statistically significant differences in baseline characteristics between the groups (p=ns). The majority of patients in both groups had a single ovarian endometrioma and the micropolypoid endometrial appearance was the predominant finding of chronic endometritis observed during hysteroscopy in both Groups. In Group A, the mean CA-125 value significantly decreased after antibiotic therapy from 58.56 U/mL (± 32.45) to 38.25 U/mL (± 17.31) (p < 0.001). No significant changes in CA-125 values were observed in Group B before and after antibiotic therapy (69.70 ± 27.42 versus 67.47 ± 24.52 U/mL, p=ns). The absolute change in CA-125 values was significantly greater in terms of reduction in Group A compared to Group B (-20.31 ± 27.09 versus -2.13 ± 12.51 U/mL; p = 0.02). Adjustment for confounders in a multivariable regression model revealed that the cure of chronic endometritis was independently associated with a significant decrease in absolute serum CA-125 levels (p = 0.006). Cyst size did not significantly change after antibiotic therapy in both groups (p=ns). Limitations, reasons for caution The main weakness of our study is that CA-125 was only measured once before and once after treatment of CE with a course of antibiotics. Moreover, our study does not allow for inferences regarding the impact of the observed reduction in serum CA-125 on the subjective symptoms related to endometriosis. Wider implications of the findings Our study constitutes the first demonstration that effective treatment of CE results in a significant decrease in a non-invasive marker of endometriosis, CA-125 supporting the emerging concept that the endometriosis might have an infectious origin. Trial registration number not applicable

O-100 Chronic endometritis - research and practice

Abstract Chronic endometritis is an inflammation of the endometrium characterized by the presence of plasma cells. Plasma cells can be identified on H&E and CD138 immunohistochemical staining by their characteristic appearance. There is a large body of evidence supporting the association between chronic endometritis and recurrent pregnancy loss (RPL), with a prevalence of approximately 30% among women with RPL (McQueen 2021). A limitation of the current literature, however, is heterogeneity of diagnostic criteria utilized and there is no consensus on the exact definition or number of plasma cells required. The treatment of chronic endometritis is oral antibiotic therapy and removal of any associated uterine pathology such as retained pregnancy tissue. Studies show that a single course of antibiotics has a cure rate of 60-94% when endometrial biopsies are repeated following treatment (Johnson 2010, McQueen 2014). Following antibiotic treatment, if resolution of chronic endometritis confirmed, women with RPL have improved live birth rates (Kimura 2019; Pirtea 2021).

P-322 Development of a CD138-based histopathological scoring system to diagnose chronic endometritis

Abstract Study question Does a standardized histopathological classification system lead to a robust interobserver agreement to diagnose chronic endometritis (CE) and can an accurate computation algorithm be developed? Summary answer The proposed scoring system has a particularly good to excellent interobserver agreement among pathologists. A machine-learning algorithm outperformed pathologists in the clinically most relevant 2-tier-system. What is known already Plasma cell (PC) presence in the stromal endometrium has been proposed as a marker for CE, yet no standardized classification system that considers the amount or distribution of PCs exists. Also, interobserver agreement has been insufficiently reported in the previous publications on the topic. Without a robust histopathological score, the potential clinical impact of CE on ART treatment outcomes cannot be investigated. This issue is strongly reflected in the heterogeneity of the current diagnostic and therapeutic approaches, specifically for patients experiencing repeated implantation failure (RIF) or recurrent pregnancy loss (RPL). Study design, size, duration A 5-tier classification system based on CD138-positive PCs (Roche B-A38/automated Ventana system) was established: class0 (no PCs), classIPC (isolated PCs), class1 (³1 cluster of 5-19 PCs/0.25mm2), class2 (³1 cluster of 20-49 PCs/0.25mm2), class3 (³1 cluster of 50 or more PCs/0.25mm2). A test set of 78 endometrial biopsies (collected over two years) was selected by a certified pathologist who sorted >1000 biopsies to ensure the full spectrum of PC counts/distribution was accounted for. Participants/materials, setting, methods The 3DHistech-platform digitized the slides (pixel size 0.2738x0.2738mm) and a scoring session was set up in the Pathomation software suite. Six pathologists scored independently after training. Overall agreement was expressed by Fleiss’ Kappa values. Pairwise interobserver agreement was calculated using Cohen’s Kappa statistics. A supervised machine-learning algorithm was developed in QuPath(V0.4.2) and considered a seventh observer in the interobserver agreement calculations. Main results and the role of chance The CD138-based semiquantitative scoring system showed particularly good to excellent interobserver agreement among all observers. Overall agreement values were 0.722 for the 5-tier system and 0.858 for the 2-tier system (0+IPC versus 1 + 2+3, which was considered the clinically most relevant classification, i.e. CE absent versus diagnosed). Pairwise interobserver agreement was 0.871-0.951. Intra-class correlations varied from 0.727 to 0.839 in the 5-tier system and 0.893 to 0.965 in the 2-tier system. All findings were statistically significant (p < 0.001). The supervised machine-learning algorithm was able to compete with human pathologist observers and outperformed them in the 2-tier system. The proposed classification system provides a framework for assessing the presence and severity of endometrial PC infiltration and can guide further research. Limitations, reasons for caution Inconsistent staining intensity, non-specific epithelial staining and background interference are common problems that might limit interlaboratory use of the algorithm. Furthermore, the algorithm has not yet been associated to patient/clinical parameters. Accurate analysis of an endometrial biopsy might still be insufficient to provide a formal diagnosis of CE. Wider implications of the findings To unravel the association between PCs in endometrial biopsies (as a proxy for the diagnosis of CE) and the reproductive outcomes following ART, a standardized methodology is of crucial importance for future studies. Higher accuracy, efficieny and automation are advantages when using computer-aided diagnostics for CE. Trial registration number BUN 143202042810

P-736 The therapeutic effect of hysteroscopic surgery on chronic endometritis in infertile women with intrauterine disorders

Abstract Study question Can chronic endometritis (CE) be treated by hysteroscopic surgery without antibiotic treatment in women with intrauterine disorders? Summary answer Most CE cases with intrauterine disorders were cured through hysteroscopic surgery without antibiotic therapy, regardless of the type of intrauterine abnormalities. What is known already Persistent inflammation of the local endometrium, CE, interferes with embryo implantation. CE is primarily caused by intrauterine infection; therefore, broad-spectrum antibiotic therapy is the current treatment for CE. Nevertheless, most cases with CE and endometrial polyps can be cured via hysteroscopic polypectomy without antibiotic therapy in our previous study. Study design, size, duration This study was a prospective cohort study approved by the Ethics Committee. To evaluate the therapeutic effect of hysteroscopic surgery on CE, the endometrial specimens for the immunohistochemistry analysis of the plasma cell marker CD138 were obtained to diagnose CE at surgery between November 2018 and June 2021. In the women diagnosed with CE, endometrial biopsy was performed without use of antibiotics in the subsequent menstrual cycle. Participants/materials, setting, methods The study population consisted of 337 consecutive infertile women who underwent hysteroscopic surgery. Eighty-nine consecutive patients without intrauterine disorders were also recruited as control group. CE was diagnosed as the presence of ≥ 5 CD138-positive cells in 10 nonoverlapping random stromal areas of high-power fields (HPF) in this study. Main results and the role of chance The prevalence of CE with ≥5 CD138-positive cells in women with no intrauterine disorder, endometrial polyps, myomas, intrauterine adhesion (IUA), and septate uterus were 15.7%, 85.7%, 69.0%, 78.9%, and 46.2%, respectively. Multivariate analysis revealed that CE was diagnosed significantly more often in the endometrial polyp (p < 0.0001, odds ratio [OR] 27.69, 95% confidence interval [CI] 15.01–51.08) and IUA groups (p < 0.0001, OR 8.85, 95%CI 3.26–24.05). The CE recovery rates by hysteroscopic surgery in the women with endometrial polyps, myomas, IUA, and septate uterus were 89.7%, 100%, 92.8%, and 83.3%, respectively (p = 0.45). Limitations, reasons for caution This study has limitations. First, some patients received a combination of estrogen and progestin or dienogest before surgery. These medicines may influence the number of CD138-positive cells. Second, ≥5 CD138-positive cells per 10 HPF were defined as the diagnosis of CE; however, different diagnostic criteria may generate different results. Wider implications of the findings CE is primarily caused by intrauterine infection due to a wide variety of microorganisms; however, most CE cases with intrauterine abnormalities were cured by hysteroscopic surgery without antibiotic use. Most CE cases associated with intrauterine abnormalities may be noninfectious CE. Trial registration number not applicable

P-323 Endometriosis and adenomyosis present lower expression in uterine natural killer cells

Abstract Study question Is there an association between endometriosis and uterine natural killer cells? Summary answer Decreasing level of uterine natural killer cells had positively associated with Endometriosis and Adenomyosis. What is known already Uterine natural killer cells (uNK) represent the predominant lymphocyte population within the decidua during implantation and in the initial stages of pregnancy. Dysregulation of uNK function has been associated with reproductive challenges, including recurrent miscarriage (RM) or recurrent implantation failure (RIF). This suggests an underlying disruption in immune activity during implantation. Endometriosis is a chronic and inflammatory disorder that usually affects the pelvic cavity and can cause severe pain during menstruation. However, there are paucity studies focus on the role of uNK in endometriosis and adenomyosis. The aim of this study was to identify the association between endometriosis and uNK. Study design, size, duration In this Prospective cohort study, 60 participants were recruited from May 2023 to January 2024 at the outpatient department of Obstetrics and Gynecology in Chang Gung Memorial Hospital, Kaohsiung Medical Center in Taiwan. The inclusion criteria were as follows: adult women of childbearing age were eligible to participate. Old age (>45 years old) patients, or patient with underlying medical disease, immune diseases and malignancy, or patient using immunosuppressant were excluded. Participants/materials, setting, methods Endometrial tissues were collected during the mid-luteal phase using an endometrial curette. The level of uNK were measured by immunohistochemistry with CD56+, and was presented in absolute number per high power filed. CD138 was also measured, and the level above 5 cell/HPF was defined as chronic endometritis. Endometriosis and adenomyosis were confirmed histologically. RM was defined as ≧2 previous miscarriages. RIF was defined as ≧2 previous failures to achieve clinical pregnancies after embryo transfer. Main results and the role of chance At least one uNK/HPF was revealed in 58 cases, 0-10uNK/HPF in 15 cases (24.5%), 11-20 uNK/HPF in 19 cases (31.6%) and above 20 uNK/HPF in 26 cases. After adjusting for covariates, patient with endometriosis and adenomyosis were positively associated with lower uNK level(low vs. high uNK(cut-off value: 20 uNK/HPF), odds ratio (OR) (95% confidence interval (CI)), 9.434 (1.101–83.33), p = 0.032; 2.000 (1.515–2.639), p = 0.015). Moreover, there are 14 patients with RM (23.3%), 26 patients with RIF (43.3%) and 7 patients with CE (11.7%). However, our study did not find significantly association between RM or RIF or CE with uNK levels. Limitations, reasons for caution Because of the single-center, Asian origin of our patients, and the sample size was relatively small. Further large-scale longitudinal studies are required to verify our findings and evaluate the underlying pathophysiology between endometriosis and uNK. Wider implications of the findings Our study highlights the significantly decreased uNK level in endometrium of women with endometriosis and adenomyosis, which may indicate some alteration in immune environment under endometriosis. Further research is warranted for understanding the immuno-modulation in endometriosis. Trial registration number not applicable

Current Status of the Diagnosis and Treatment of Adenomyosis

Adenomyosis refers to the endometrial glands and mesenchyme that invade the myometrium through the basal layer, and under the action of hormones, repeated bleeding, myofibrous connective tissue hyperplasia formed by diffuse or limited lesions. It is a common disease in women of childbearing age and is more common in women over 40 years of age with menstruation. In recent years, the age of onset of the disease tends to be younger, which may be related to the various uterine surgical operations in clinical work, such as abortion, childbirth, curettage, chronic endometritis, and so on. The mechanism of the disease is currently thought to be due to the invasion of the basal endometrium into the myometrium for growth, but the ectopic endometrium is immature, has reactive changes to estrogen, and is insensitive to progesterone. Its main symptoms are increased menstrual flow, dysmenorrhea, and low fertility, which seriously affect the quality of life of patients. Among them, the incidence of excessive menstrual flow is 40%–50% and the incidence of dysmenorrhea is 15%–30%. There are numerous treatments available for adenomyosis aimed at reducing menstrual flow, relieving dysmenorrhea, and improving fertility. A brief review of the various treatments available for adenomyosis in the clinic is as follows.

P-293 Influence of the endometrial microbiota composition on the clinical outcomes of egg donation PGT-A cycles with controlled endometrial receptivity

Abstract Study question Does the endometrial microbiota composition and diversity influence embryo implantation and pregnancy evolution in assisted reproduction treatment (ART) cycles? Summary answer Endometrial microbiota composition influences ART success. Detection of endometrial pathogens is associated with poor outcomes whereas sterile endometria show the highest pregnancy and live-birth rates What is known already The endometrial microbiota has emerged as a possible influencing factor in the results of ART. Recent research suggests its impact on female reproductive health, particularly in patients with chronic endometritis (CE), where the presence of microbial pathogens associated with this condition has been linked to infertility. In turn, the bioregulatory role of species of Lactobacillus in this tissue has been explored, although its essentiality or benefit for female reproductive function continues to be topics of debate. Study design, size, duration This is a case-control retrospective study analysing for the first time the influence of the endometrial microbiota composition on the clinical outcomes of 220 women undergoing egg donation cycles with Preimplantation Genetic Testing for Aneuploidy (PGT-A) and controlled endometrial receptivity between March 2016 and April 2021 in IVF-Life Alicante (Spain). ART results after the transfer of a single euploid blastocyst in the WOI of patients with different endometrial microbiota profiles were analysed and compared. Participants/materials, setting, methods Presence of 18 microbial CE pathogens and 4 Lactobacillus species was determined by high-throughput qPCR (MicrobioMap®, iGLS) in endometrial samples obtained during the WOI of a hormone replacement therapy cycle. In all cases, PGT-A by next generation sequencing (NGS) (EmbryoMap, Vitrolife) and study of endometrial receptivity by gene expression analysis (ER Map, iGLS) were performed. Clinical outcomes (β-hCG+, β+ and live birth, LB) in relation to the endometrial microbiota profile were analysed and compared. Main results and the role of chance In the study, 31.8% of patientś endometria were identified without microbial detection, 40% exclusively with Lactobacillus, 13.2% with pathogens only, and 15% with both. Clinical results revealed significant differences in β+ rates among the groups (p < 0.05). The absence of microorganisms was associated with higher success rates (β + 72.9%), while the presence of pathogens significantly reduced pregnancy success (β + 41.4%). A similar trend was observed in LB rates, although it did not reach statistical significance (44.3% and 24.1%, respectively). The presence of Lactobacillus alongside pathogens improved clinical outcomes (β + 57.6% LB 48.5%). Interestingly, exclusive presence of Lactobacillus showed lower implantation rates than patients without microbial detection (β + 58%). These findings highlight the impact of microbial composition on the clinical outcomes of ART cycles, underlining the association between endometrial microbiota patterns and pregnancy success. Limitations, reasons for caution This study is constrained by its retrospective nature, emphasizing the need for further validation through randomized controlled trials, non-selection studies, or other investigative approaches to confirm the extent of any clinical benefits. Endometrial biopsies were obtained transcervically, while executed with utmost care, risk of contamination cannot be completely excluded. Wider implications of the findings The composition and diversity of the endometrial microbiota is key for ART success. A sterile endometrial environment offers optimal conditions for implantation and pregnancy. The study highlights the potential of Lactobacillus in counteracting the negative impact of pathogenic presence. Trial registration number not applicable

P-306 GnRH agonists exert a positive influence on regulatory immune cells in the endometrium of women with adenomyosis

Abstract Study question How does treatment with GnRH-agonist (GnRH-a) prior to frozen embryo transfer (FET) in women with adenomyosis affect immune cell populations in endometrium and peripheral blood? Summary answer GnRH-a induces a decrease in monocytes and an increase in CD4+T-cells in peripheral blood and a decrease classical monocytes and T-regulatory cells in the endometrium What is known already Adenomyosis is associated with lower implantation and higher miscarriage rates. Observational studies have reported improved pregnancy outcomes in women with adenomyosis after assisted reproductive technologies (ART) and pre-treatment with GnRH-a prior to FET. However, the specific mechanisms of GnRHa action beyond central hormonal suppression remain unclear, but may be mediated through local and/or systemic immunomodulation. Study design, size, duration Prospective cohort study including infertile women with adenomyosis and GnRH-a treatment ≥3 months prior to FET. Pre- and post-treatment analysis of blood and endometrium samples were compared. Recruitment is ongoing with n = 30 women included thus far, 16 of whom have completed the study, while the remaining are still undergoing GnRH-a therapy. Participants/materials, setting, methods Adenomyosis was diagnosed sonographically if ≥ 2 criteria published by the MUSA group were met. Peripheral blood and endometrial samples were obtained before and after treatment with GnRH-a. Plasma cells and uterine Natural Killer (uNK) cells in endometrial biopsies were quantified with immunhistochemistry (IHC), and leukocyte populations in all samples were analysed using flow cytometry (FC). Pre- and post-treatment levels of immune cells and percentage of leukocyte populations were compared using Wilcoxon rank-sum tests (p < 0.05 significant) Main results and the role of chance Interim analysis of immune cell populations in peripheral blood and endometrium of the 16 women who already completed the study was performed. At baseline, IHC showed elevated plasma cell concentrations indicating chronic endometritis in 3/30 patients (10%), while uNK cells were elevated (>300/mm2) in 13/30 patients (43.3%). FC analysis of peripheral blood showed a significant decrease in percentage of monocytes (p = 0.01) and increase in percentage of T-cells (p = 0.03), specifically concentration of CD4+T-cells (p = 0.03), after treatment with GnRH-a as compared to pre-treatment levels. In the endometrium, following GnRH-a therapy, we observed a decrease in both the percentage of classical monocytes (p = 0.03) and T-regulatory cells (p = 0.03). All 16 participants who completed the study already underwent FET, resulting in ten pregnancies (62.5%), although four resulted in miscarriage, while the outcome of the remaining pregnancies is still pending. Limitations, reasons for caution These are preliminary results whose generalizability needs to be confirmed in a larger study population. No correction for multiple comparisons was performed and significant findings have to be interpreted with caution. Wider implications of the findings Elevated uNK on IHC cells seen at baseline may be associated with implantation failure, miscarriage. CD4+ and DN T-cells are important mediators of reproductive immune tolerance. In women with adenomyosis, GnRH-a may have a positive impact on these regulatory immune cells in peripheral blood as well as in the endometrium. Trial registration number Not applicable

O-278 The vaginal and endometrial microbiome: do they tell the same story?

Abstract Study question Is the composition of the endometrial microbiome comparable to that of the vagina and can vaginal sampling provide sufficient information to characterize the uterine microbiome? Summary answer The compositions of the endometrial and vaginal microbiome are largely comparable and therefore, in most cases, vaginal sampling is sufficient to characterize the uterine microbiome. What is known already A dysbiotic endometrial microbiome (i.e., a shift from a predominance of beneficial bacteria to less favourable species) has been reported in association with adverse pregnancy outcomes in assisted reproductive treatment (ART). If dysbiosis is detected, antibiotics or probiotics can be administered to restore an optimal microbiome. However, characterization of the endometrial microbiome is challenging, involving invasive sampling, and technical difficulties due to the low microbial mass in the endometrium. In contrast, vaginal sampling is considered minimally invasive and microbial analysis is technically less complex. It is important to clarify whether the microbiomes of the endometrium and the vagina are comparable. Study design, size, duration A prospective multi-centre study including 60 ART patients was conducted from June 2022 to August 2023. During the luteal phase (on average day-19), paired vaginal swabs and endometrial biopsies were collected sequentially and stored in a preservation medium for further analysis. Patients and physicians were also asked to complete a questionnaire to identify any lifestyle or medical factors that may have differentially affected the microbial composition of the vagina and endometrium. Participants/materials, setting, methods A carefully validated qPCR methodology was used to accurately assess the presence and relative abundance of the four major lactobacillus species associated with eubiosis (crispatus, gasseri, iners, and jensenii) and the 15 most common bacterial species implicated in dysbiosis. Additionally, the relative abundance of microbial and human DNA was examined. Of note, endometrial analysis required additional tissue lysis. Furthermore, due to the low microbial DNA content in endometrial samples, preamplification was necessary prior to qPCR. Main results and the role of chance The proportion of microbial versus human DNA was approximately 90 times higher in vaginal samples compared to endometrial samples (p < 0.0001). However, the microbial compositions of both the endometrium and the vagina showed remarkable similarities. Lactobacillus species were predominant at both sites, accounting for an average of 86% and 89% of the bacterial population in the vagina and endometrium, respectively (p = 0.6). Of the dysbiotic species, Gardnerella vaginalis was the most common, accounting for 8% (vagina) and 7% (endometrium) of the total bacterial population (p = 1). There was no difference in the average number of distinct microbial species between the two niches (1.8 vs. 2.1; p = 0.3). Direct comparison of paired samples highlighted the high similarity of microbial compositions between both sites and showed strong correlations of species abundances in individual patients (L.crispatus: r = 0.9, L.iners: r = 0.9, L.gasseri: r = 1, L.jensenii: r = 0.9, G.vaginalis: r = 0.7; p < 0.0001/all species). However, the microbial composition differed in four patients (6.6%), with three having a dysbiotic vaginal profile (≥50% dysbiotic species) but a eubiotic endometrial profile (≥50% lactobacillus species) and one showing the reverse pattern. The medical conditions of two patients, including chronic endometritis and use of antibiotics and probiotics in the preceding cycle, may account for the observed differences. Limitations, reasons for caution The species analysed were carefully selected to ensure a comprehensive analysis. Nevertheless, the potential presence of unevaluated species could impact the results. While the included patients displayed diversity in their reproductive histories, it is important to acknowledge that the observed results may still be influenced by underlying causes of infertility. Wider implications of the findings The close similarity between the microbiomes at the two sites investigated suggests that minimally invasive vaginal sampling may be sufficient to characterise the endometrial microbiome. The ease of vaginal sampling and processing is expected to improve patient recruitment in microbiome research and facilitate easier application of clinical microbiome tests. Trial registration number not applicable

Association between endometrial polyps and chronic endometritis

Background Chronic endometritis (CE) is a persistent inflammatory disorder of the endometrium. It is now diagnosed by observing the presence of plasma cell infiltration in the stromal tissue of the endometrium. Aim This study aimed to examine the potential correlation between endometrial polyps (EPs) and CE. Patients and methods This prospective cohort study was carried out on 60 women, aged from 20 to 50 years old, diagnosed to have EP by three dimensional transvaginal ultrasound with color doppler, during a diagnostic workup for abnormal uterine bleeding, infertility, or accidentally discovered by ultrasound. Results Suspicious manifestation of CE in patients with EP as (hyperemia and stromal oedema) was significantly higher in patients with CE than patients without CE (P value<0.001) by hysteroscopy. Regarding histopathology, simple EP was present in 33 (55%) patients, Adenomyomatous polyp was present in eight (13.33%) patients, angiofibromatous polyp was present in one (1.67%) patients and polypoid endometrial hyperplasia was present in 18 (30%) patients. regarding the relation between EP and CE 15 (25%) patients had CE by histopathology. Conclusions In pCE, -menopausal women identified with EP by three dimensional transvaginal ultrasonography, CE and EPs may be dependent and two phases of the same pathogenic process. Either single or many EPs positively correlate with CE. CE prevalence was comparable for single- and multiple-polyp individuals.

Chronic endometritis multiplies the recurrence risk of endometrial polyps after transcervical resection of endometrial polyps: a prospective study

BackgroundTo investigate the impact of chronic endometritis (CE) on the recurrence of endometrial polyps (EPs) in premenopausal women after transcervical resection of endometrial polyps (TCRP).MethodsThis prospective study enrolled 507 women who underwent TCRP between January 1, 2022 and December 31, 2022. The patients were divided into a CE group (n = 133) and non-CE group (n = 374) based on the expression of CD138 in the endometrium. The EP recurrence rate at 1 year after TCRP was compared between the CE and non-CE groups and between groups with mild CE and severe CE. The impact of CD138 expression by resected EPs on EP recurrence also was investigated.ResultsThe EP recurrence rate at 1 year post-TCRP was higher in the CE group than in the non-CE group (25.6% vs. 10.4%) and also higher in the severe CE group than in the mild CE group (34.5% vs. 18.7%). Additionally, the EP recurrence rate was higher among patients with CD138-expressing EPs than among those with EPs lacking CD138 expression (30.5% vs. 6.5%). The odds ratio (OR) for EP recurrence in the CE cohort compared with the non-CE cohort was 3.10 (95% confidence interval [CI] 1.84–5.23) after adjustment for EP number and precautions against EP recurrence. The ORs for EP recurrence in patients with mild CE and severe CE were 2.21 (95%CI 1.11–4.40) and 4.32 (95%CI 2.26–8.26), respectively. Similarly, the OR for EP recurrence in cases with CD138-expressing EPs relative to cases with EPs lacking CD138 expression was 6.22 (95%CI 3.59–10.80) after adjustment for EP number and precautions against EP recurrence.ConclusionsCE multiplied the recurrence rate of EPs in premenopausal women after TCRP, and this effect positively correlated with CE severity. CD138 expression by EPs also was associated with a higher risk for EP recurrence.

The Impacts of Inflammatory and Autoimmune Conditions on the Endometrium and Reproductive Outcomes.

Background: A healthy pregnancy begins with an adequate endometrial state, even before the arrival of a blastocyst. Proper endometrial priming and the development of a tolerogenic decidua are key steps in creating the perfect environment for implantation and pregnancy. In these processes, the involvement of the maternal immune system seems to be of great relevance, modulating the different decidual immune populations to prepare the endometrium for a potential pregnancy. However, certain local pathologies of an inflammatory and autoimmune nature appear to have a direct impact on these phenomena, thus altering patients' reproductive outcomes. Methods: This literature review analyzes original articles, reviews, systematic reviews, and meta-analyses published between 1990 and 2024, concerning the impact of different inflammatory and autoimmune conditions on endometrial status and fertility. The included papers were obtained from Medline (Pubmed) and the Cochrane library. Results: There is evidence that endometriosis, adenomyosis, and chronic endometritis, through the promotion of a chronic inflammatory environment, are capable of altering endometrial immune populations, and, thus, processes essential for early pregnancy. Among other effects, these conditions have been linked to impaired decidualization, alterations in progesterone responsiveness, and hindered placentation. Similarly, antiphospholipid syndrome (APS), thyroid dysfunction, diabetes, and other pathologies related to glucose and gluten metabolism, due to their autoimmune nature, also appear to have a local impact on the uterine environment, affecting reproductive success through different mechanisms, including altered hormonal response and, again, impaired decidualization. Conclusions: The management of inflammatory and autoimmune diseases in assisted reproduction patients is gaining importance due to their direct impact on the endometrium. It is necessary to follow current expert recommendations and established therapeutic approaches in order to improve patients' prospects, ranging from antibiotic treatment in chronic endometritis to heparin and aspirin in APS, as well as hormonal treatments for endometriosis/adenomyosis or a gluten-free diet in celiac disease. All of them and the rest of the therapeutic perspectives, both current and under investigation, are presented throughout this work, assessing the possible improvements for reproductive outcomes.

Chronic endometritis - a constantly discussed issue in infertile women.

A review of current knowledge on the pathophysiology, diagnostic and treatment options for chronic endometritis in infertile women. One of the major causes of failed in vitro fertilization (IVF) is undiagnosed intrauterine pathologies, including chronic inflammation of the uterine mucosa - chronic endometritis. However, some authors relativize the negative impact of chronic endometritis on reproductive outcomes. The etiopathogenesis of chronic endometritis is due to qualitative and quantitative changes in the endometrial microbiome with abnormal multiplication of microorganisms naturally occurring in the uterine cavity or vagina. There is no uniform consensus on the most common pathogen causing chronic endometritis. It is characterized by infiltration of plasma cells into the endometrial stroma outside the menstrual cycle, accompanied by hyperaemia and endometrial oedema. Clinical symptoms are very mild or absent. The diagnosis of chronic endometritis is often difficult because there is no specific clinical or laboratory diagnostic method. The following investigative options are commonly used for the diagnosis of chronic endometritis: diagnostic hysteroscopy, histopathological examination of the endometrium including CD 138 immunohistochemistry and culture from the uterine cavity. However, standardised international hysteroscopic and histopathological criteria for accurate diagnosis of chronic endometritis are still lacking. Empirically administered antibiotic therapy improves the success rate of pregnancy and delivery of a viable foetus in infertile patients with proven chronic endometritis. In addition to reviewing the current knowledge of chronic endometritis, this article discusses the importance of hysteroscopy in the diagnostic process. Chronic endometritis is often a clinically silent disease with negative impact on reproduction in infertile women. Although there are still many unresolved issues, the introduction of hysteroscopy into the diagnostic process is important for clinical practice; however, hysteroscopy even in combination with histological examination of the endometrium, often does not allow an unequivocal diagnosis of chronic endometritis. Further prospective randomised studies in a selected group of women with proven chronic endometritis and repeated failure to implant proven euploid embryos should refine this knowledge.

The changes in ultrasound parameters during treatment of chronic endometritis depending on the morphological type in women of reproductive age

Objective: to evaluate the dynamics of echographic parameters of structural changes in the endometrium depending on the morphological type of chronic endometritis (CE) before and after etiotropic therapy.Material and methods. A retrospective cohort based on the results of examination of 140 patients of reproductive age with a verified diagnosis of CE before and after complex etiotropic therapy. A pelvic ultrasound was performed in the 1st phase of the menstrual cycle with measurements of the endometrial and uterine volume, followed by a calculation of the percentage endometrial/uterine volume ratio (EV/UCV). The groups of hypoplastic, mixed, and hyperplastic morphotypes were formed according to the values of EV/UCV. The B-mode examination included the assessment of the structure and echogenicity of the uterine cavity mucosa; the line of closure or divergence of the endometrial layers; the external contour of M-echo; the presence of liquid in the uterine cavity, and acoustic artifacts, in particular reverberation, as a sign of gas bubbles.Results. An increase in the thickness and volume of the endometrium, and EV/UCV was obtained after therapy in the hypoplastic morphotype. There were no changes in the thickness or volume of the endometrium in the mixed morphotype. A significant decrease in the thickness and volume of the endometrium, and EV/UCV were found in the hyperplastic morphotype. In all morphotypes, the endometrium remained mostly hyperechoic and heterogeneous, with an abnormal midline.Conclusion. The hypoplastic and mixed morphotypes are characterized by more persistent endometrial changes that are difficult to treat. Pathological signs were eliminated much more often in the hyperplastic morphotype. The results of the study demonstrate the absence of a complete reduction in the analyzed ultrasound criteria of CE after end of treatment for all morphological types.

Bridging the Diagnostic Gap between Histopathologic and Hysteroscopic Chronic Endometritis with Deep Learning Models.

Chronic endometritis (CE) is an inflammatory pathologic condition of the uterine mucosa characterized by unusual infiltration of CD138(+) endometrial stromal plasmacytes (ESPCs). CE is often identified in infertile women with unexplained etiology, tubal factors, endometriosis, repeated implantation failure, and recurrent pregnancy loss. Diagnosis of CE has traditionally relied on endometrial biopsy and histopathologic/immunohistochemistrical detection of ESPCs. Endometrial biopsy, however, is a somewhat painful procedure for the subjects and does not allow us to grasp the whole picture of this mucosal tissue. Meanwhile, fluid hysteroscopy has been recently adopted as a less-invasive diagnostic modality for CE. We launched the ARCHIPELAGO (ARChival Hysteroscopic Image-based Prediction for histopathologic chronic Endometritis in infertile women using deep LeArninG mOdel) study to construct the hysteroscopic CE finding-based prediction tools for histopathologic CE. The development of these deep learning-based novel models and computer-aided detection/diagnosis systems potentially benefits infertile women suffering from this elusive disease.

Chronic endometritis. Local prooxidant, antioxidant and immunometabolic disorders. An open-label, prospective, randomized study

Aim. To determine local features of lipoperoxidation processes, antioxidant defense, state of matrix metalloproteinases in chronic endometritis. Materials and methods. Eighty women aged 29.33±6.71 (min-max [24–36]) with histologically and immunohistochemically confirmed chronic endometritis and a history of reproductive losses were examined (group 1). The control group consisted of 30 patients without chronic endometritis confirmed by the results of a histochemical study and no history of reproductive losses, suffering from infertility of tubal-peritoneal origin at the age of 30.11±6.9 years (min-max [24–37]; group 2). All 130 patients underwent transvaginal echography of the pelvic organs, and histological and immunohistochemical examination of endometrial samples was performed. The activity of lipid peroxidation factors was analyzed: primary, secondary and final products of lipid peroxidation in heptane and isopropanolol fractions of uterine cavity aspirate, enzymes of the antioxidant system: superoxide dismutase, catalase, glutathione peroxidase, deoxyribonuclease I (DNase), by spectrophotometric method, remodeling factors – matrix metalloproteinases MMP-2, -9 by flow fluorimetry. Results. In patients of group 1, according to transvaginal echography of the pelvic organs, M-echo was 6.29±1.22 mm, in group 2 – 9.10±1.15 mm. In chronic endometritis, disruption of pro-oxidant and activity of antioxidant factors in the endometrium in women with chronic endometritis and a history of reproductive losses. In the heptane fraction of the phenolic extract, the concentration of primary products of lipid peroxidation (diene conjugates) was 12.98% higher than in the control, the content of secondary products of lipid peroxidation (ketodienes) was higher by 15.45%, conjugated trienes by 18.67% higher than the values in the control group, which indicates increased lipid peroxidation of endometrial cell membranes during CE. In the isopropanol phase, the products of lipid peroxidation of phospholipid acyl residues are detected. In the isopropanol fraction of the lipid extract, the amount of diene conjugates was higher, ketodienes by 24.32% and conjugated trienes by 26.14%. An increase in the activity of the enzymes superoxide dismutase by 23.98%, catalase by 14.34%, glutathione peroxidase by 12.39%, and DNase by 2.9 times was recorded compared to the indicators of group 2. Conclusion. Chronic endometritis is accompanied by changes in the system of pro-oxidant and antioxidant factors, the content of tissue remodeling products. The pathogenetic changes underlying oxidative stress in the endometrium may be increased leukocyte infiltration, imbalance of primary, secondary and end products of lipid peroxidation, enzymes superoxide dismutase, catalase, glutathione peroxidase, deoxyribonuclease I (DNase), expression of matrix metalloproteinases-2, -9.

Oil-soluble contrast medium bathing attenuated endometrial inflammation and improved endometrial receptivity in women with recurrent implantation failure: a descriptive study

BackgroundThe oil-soluble contrast medium used in hysterosalpingography has been shown to have a fertility-enhancing effect, but the underlying mechanism is unclear, especially regarding the role of window of implantation (WOI). This study aimed to assess the endometrial immunological impact of the WOI before and after bathing with the oil-soluble contrast medium in women with recurrent implantation failure (RIF).MethodsThis descriptive study involved two medical centers between December 18, 2019, and December 30, 2020. We included infertile women who underwent three or more transfer cycles, cumulative transplantation of at least four high-quality cleavage-stage embryos or three high-quality blastocysts without clinical pregnancy, and high-quality frozen embryos that were still available for implantation. Patients received 5 ml of ethiodized poppyseed oil bathing, endometrial biopsy around bathing, and frozen-thawed embryo transfer (FET) within four menstrual cycles after bathing. Patients were excluded if failure to complete anyone. Data on the baseline characteristics and clinical data of the FET cycles were collected, and endometrial biopsy specimens were collected in the luteal phase before and after bathing and subjected to immunohistochemistry. The number of CD56 and CD138 positive cells and H-score of expression of ανβ-3 and HOXA10 in endometrium were collected.ResultsThirty-four patients were initially enrolled in the study; ultimately, twelve patients with a median age of 32.5 years (range 27–40 years) completed the research. The median number of embryo transfer cycles was three (range 3–8). A total of 4 of 12 women (33.33%) were diagnosed with chronic endometritis before oil-soluble contrast bathing. After bathing, the median numbers of CD138-positive cells in endometrium decreased from 0.75 (range 0–13.5) to 0.65 (range 0–6), P = 0.035; additionally, the H-score of expression of ανβ-3 in endometrium increased from 148.50 ± 31.63 to 175.58 ± 31.83, P < 0.001. The thickness of the endometrium also significantly increased (8.90 ± 1.45 mm vs.10.11 ± 1.98 mm, P = 0.005). However, no consistent changes were found in the expression of CD56 and HOXA10 in the endometrium. Five patients experienced biochemical pregnancies (41.67%), four had clinical pregnancies (33.33%), and three achieved live births following oil-soluble contrast bathing (25%).ConclusionsThese results suggest that oil-soluble contrast medium bathing decreased CD138-positive cells and upregulated expression of ανβ-3 during WOI in patients with RIF. This histological impact of endometrium may result in enhanced fertility during FET cycles. Investigating the ability of intrauterine bathing with lower-dosage oil-soluble contrast to improve pregnancy in the RIF population is warranted.

Морфологические особенности эндометрия в прегравидарном периоде, хориона и плаценты при беременности, наступившей в результате экстракорпорального оплодотворения, у пациенток с хроническим эндометритом (вторичные результаты рандомизированного контролируемого испытания «ТЮЛЬПАН 2»)

Морфологические особенности эндометрия в прегравидарном периоде, хориона и плаценты при беременности, наступившей в результате экстракорпорального оплодотворения, у пациенток с хроническим эндометритом (вторичные результаты рандомизированного контролируемого испытания «ТЮЛЬПАН 2»)

Microbiome dysbiosis in patients with chronic endometritis and Clostridium tyrobutyricum ameliorates chronic endometritis in mice

Chronic endometritis is associated with the imbalance of female reproductive tract microbiota and pathogenic microbial infection. This study aimed to identify the specific changes in the endometrial microbiome in patients with endometritis and to explore how Clostridium tyrobutyricum (C.t) influences the progression of endometritis in mice for further elucidating endometritis pathogenesis. For this purpose, endometrial tissues from 100 participants were collected and divided into positive, weakly positive, and negative groups based on CD138 levels, while endometrial microbiome differences were detected and analyzed using 16S rRNA gene sequencing. Staphylococcus aureus (S. aureus)-induced endometritis mouse model was established, followed by treatment with C.t, and inflammatory response, epithelial barrier, and TLR4/NF-κB pathway were evaluated. Results showed that α- and β-diversity was significantly lower in the positive group compared with the weakly positive or negative groups, where the negative group had more unique operational taxonomic units. The abundance of Proteobacteria was found to be increased, while that of Actinobacteria, Firmicutes, and Bacteroidetes was found to be reduced in the positive group, while the area under the curve value was found to be 0.664. Furthermore, C.t treatment resulted in the alleviation of S. aureus-induced inflammatory response, epithelial barrier damage, and activation of the TLR4/NF-κB pathway in mice. Clinical samples analysis revealed that the diversity and abundance of microbiota were altered in patients with endometritis having positive CD138 levels, while mechanistic investigations revealed C.t alleviated S. aureus-induced endometritis by inactivating TLR4/NF-κB pathway. The findings of this study are envisaged to provide a diagnostic and therapeutic potential of microbiota in endometritis.