Endometritis - Diagnosis,Treatment and its impact on fertility - A Scoping Review

Defining a panel of principal bacteria associated with endometritis

The aim of this study is to present a panel that includes the main bacterial genera associated with endometritis. We conducted a search using the terms "endometritis women" OR "female endometritis" OR "pelvic inflammatory disease" AND bacteria* OR "uterine microbiome" in two databases: PubMed and Web of Science, without language or publication year restrictions. The panel is based on an analysis of 40 studies published over the past 38 years. We identified 31 bacterial genera, with the following five being the most frequently cited: Chlamydia and Ureaplasma with 11.03% each, Streptococcus and Mycoplasma with 9.56% each, and Enterococcus with 8.09%. Regarding its etiological aspects, we found that bacterial infection is the most prevalent cause of the disease, occurring because of invasive procedures such as curettage, cesarean section, or insertion of intrauterine devices (IUDs), among others. These events facilitate the entry of pathogenic microorganisms into the uterus, resulting in an inflammatory response and subsequent development of endometritis. The main techniques used to detect these pathogens were microbial culture, Polymerase Chain Reaction (PCR), and Next-Generation Sequencing, with microbial culture being the most employed, followed by PCR or a combination of both techniques. This diversity of techniques has significantly expanded our understanding of the presence and identification of microorganisms associated with the pathophysiology of endometritis. Therefore, it is understood that these findings serve as a foundation for further investigations of microorganisms related to endometritis, and such analyses will help to clarify the relationship between endometritis and the bacteria that cause it.

Development of a novel chimeric lysin to combine parental phage lysin and cefquinome for preventing sow endometritis after artificial insemination

Sow endometritis is usually caused by multiple species of pathogenic bacteria. Numerous isolates from endometritis patients have developed antimicrobial resistance. Thus, novel antibacterial agents and strategies to combat endometritis are needed. A total of 526 bacteria, including Staphylococcus spp. (26.3%), Streptococcus spp. (12.3%), E. coli (28.9%), Enterococcus spp. (20.1%), Proteus spp. (9.5%), and Corynebacterium spp. (2.8%), were isolated from sows with endometritis. We constructed a novel chimeric lysin, ClyL, which is composed of a cysteine- and histidine-dependent amidohydrolase/peptidase (CHAP) catalytic domain from the phage lysin LysGH15 and a cell wall-binding domain (CBD) from the prophage lysin Lys0859. The activities of ClyL and Lys0859 were most pronounced for the Staphylococcus and Streptococcus strains isolated from sow endometritis and bovine mastitis, respectively. ClyL and Lys0859 were combined to create a phage lysin cocktail, which demonstrated a synergistic effect against the coinfection of Staphylococcus and Streptococcus in vitro and in vivo. Furthermore, the combination of phage lysin cocktail and cefquinome had a synergistic bactericidal effect on boar semen that did not influence the activity of sperm. Remarkably, the incidence rate of sow endometritis was 0% (0/7) when the combination of phage lysin cocktail and cefquinome was used in semen via artificial insemination compared with 50% (3/6) when PBS was administered. Overall, the administration of a phage lysin cocktail and cefquinome in semen via artificial insemination is a promising novel strategy to prevent sow endometritis after artificial insemination.

The Role of Endometrial Microbiota in Fertility and Reproductive Health: A Narrative Review

This review explores the correlation between endometrial microbes and infertility, focusing on the impact of endometrial microbiota on fertility outcomes. The healthy status of uterine microorganisms, predominantly Lactobacillus, plays a crucial role in reproductive health. Studies have shown that the endometrial microbiota composition changes with hormonal fluctuations during the menstrual cycle, affecting endometrial receptivity and embryo implantation. The presence of specific bacteria, such as Lactobacillus species, has been associated with successful pregnancy outcomes, while dysbiosis in the endometrial microbiota has been linked to implantation failure and infertility. Factors like age, hormonal changes, and immune responses influence the composition of endometrial microbes, impacting fertility. Chronic endometritis, characterized by inflammation of the endometrium, has been linked to recurrent implantation failure and infertility. Understanding the complex interactions between endometrial microbiota, immune responses, and hormonal influences is crucial for improving fertility treatments and outcomes.

A Unique Case of Fungal Endometritis Caused by Aspergillus quadrilineatus in an Immunocompetent Woman and Literature Review

Abnormal uterine bleeding (AUB) is a common gynecological concern often attributed to hormonal disorders, malignancies, or infections. While bacterial and viral infections are frequently investigated, fungal infections, such as aspergillosis, are often overlooked. This case report highlights a rare instance of endometrial aspergillosis caused by Aspergillus quadrilineatus in an immunocompetent woman. A 64-year-old woman presented with persistent vaginal bleeding. Histopathological examination of endometrial tissue revealed septate hyphae consistent with fungal infection. Molecular analysis identified the causative agent as A. quadrilineatus. The A. quadrilineatus isolate demonstrated susceptibility to various antifungal agents, including azoles and amphotericin B. This report emphasizes the need for increased awareness of fungal infections, including aspergillosis, as a potential cause of AUB. Further research is needed to enhance understanding of the epidemiology, risk factors, and clinical manifestations of endometrial aspergillosis.

Alterations in Implantation Genes and Dendritic Cells in Endometrial Samples After Antibiotic Treatment

Background/Objectives: This retrospective study assessed the impact of chronic endometritis (CE) on the expression of implantation genes HOXA10 (Homeobox A10) and IGF-1 (insulin-like growth factor 1), and on dendritic cells before and after antibiotic treatment, as well as on clinical reproductive outcomes. Methods: The study was conducted from 2021 to 2022. Ten assisted reproductive technology patients who underwent an endometrial biopsy before antibiotic treatment, confirming the diagnosis of CE, and a second biopsy after completing a course of 100 mg doxycycline twice daily for 14 days were included. Paraffin-embedded endometrial samples from these patients were obtained from the pathology department. The samples were evaluated for quantifying implantation genes HOXA10 and IGF-1 using RT-PCR, and for identification of dendritic cells using immunohistochemical staining of CD141. Conceptions and live births were also evaluated. Results: Endometrial expression of HOXA10 and IGF-1 genes was significantly elevated after antibiotic treatment and expression of dendritic cells CD141 was decreased. Eight of the ten patients required second-line antibiotic treatment due to persistent CE. Six patients conceived and delivered. Conclusions: CE is reversible with antibiotic treatment that resulted in improvements in implantation genes and clinical results. A high proportion of patients required broader spectrum antibiotic treatment.

Advancements in Hysteroscopic Diagnosis and Management of Endometritis

Infertility remains a complex clinical challenge, with intrauterine pathologies contributing to a significant percentage of in vitro fertilization (IVF) failures. Chronic endometritis (CE) has gained attention due to its potential association with unexplained infertility and recurrent miscarriage. This review explores the role of hysteroscopy in diagnosing and treating CE. The endometrium undergoes dynamic changes orchestrated by ovarian steroids, and disturbances may lead to CE, characterized by plasma cell infiltration. Diagnosis traditionally relies on histopathologic examination, but hysteroscopy offers real-time imaging, revealing the specific macroscopic alterations associated with CE. However, diagnostic accuracy varies, prompting the need for standardized criteria. CE has been linked to poor reproductive outcomes, emphasizing the importance of effective treatment. Antibiotic therapy is a common approach, with doxycycline as the first-line regimen. Hysteroscopic polypectomy, targeting non-infectious CE, emerges as a promising treatment, demonstrating fertility benefits. The review underscores the significance of hysteroscopy in diagnosing and treating CE, providing insights into its impact on reproductive outcomes in infertile women. Further prospective studies are needed to validate these findings and establish unified diagnostic criteria.

Chronic Endometritis and Endometriosis: Two Sides of the Same Coin?

Both chronic endometritis and endometriosis are common entities in infertile patients. The association and the co-existence of these two entities are poorly evaluated. The aim of this systematic review and meta-analysis was to examine the association between chronic endometritis and endometriosis and to find the prevalence of chronic endometritis in women with endometriosis. A systematic electronic search was conducted using the MEDLINE, Scopus and Cochrane databases up to May 2022. Observational studies which examined the prevalence of chronic endometritis in women with endometriosis were included. Newcastle-Ottawa Scale was used for the quality assessment. Odds ratios (OR) with 95% confidence intervals (CIs) for dichotomous outcomes and pooled prevalences with 95% CIs were calculated. 855 studies were identified, of which six studies were included in the systematic review and five in the meta-analysis. The prevalence of chronic endometritis in women with endometriosis was 28%, with higher frequency observed in women with endometriosis rASRM stage III-IV (43%) in comparison to women with endometriosis rASRM stage I-II (25%). The meta-analysis showed a significantly higher chronic endometritis in women with endometriosis in comparison to the control group (five studies, 264 endometriosis vs. 435 control, OR = 2.07; 95% CI 1.11-3.84, I2 43%, p = 0.02). The present meta-analysis showed a significantly higher risk of chronic endometritis in women with endometriosis in comparison to the control group. These findings contribute to a better understanding of the causes and consequences of endometriosis and chronic endometritis and may help in the development of more efficient treatment strategies for women with associated infertility.

Uterus didelphys: the first case report on molecular profiling of endometrial tissue from both uterine cavities

BACKGROUND

A didelphic uterus represents a unique and infrequent congenital condition in which a woman possesses two distinct uteri, each with its own cervix. This anomaly arises due to partial or incomplete merging of the Müllerian ducts during the developmental stages in the womb. Accounting for uterine malformations, a didelphic uterus is a relatively rare condition, affecting approximately 0.5-2% of the population and is considered one of the more uncommon types of uterine abnormalities.

METHODS

This case report aims to study the physical separation in uterine didelphys and its impact on endometrial microbiome and inflammation, and the patterns of endometrial receptivity observed.

RESULTS

Endometrial receptivity analyses revealed a similar receptive state in both uteri, both in the early receptive phase. Differential markers of chronic endometritis, including CD138, and MUM1-positive cells, were observed when comparing endometrial biopsies from both uteri. The right uterus exhibited a higher prevalence of these positive cells. Regarding the microbiome, significant differences were found between the uteri, notably in the right uterus, a clear non-dominance of lactobacilli and the presence of genera such as Staphylococcus, Streptococcus, and Acinetobacter. Additionally, the right uterus presented a less 'favourable' microenvironment, a characteristic that was also reflected in the right cervix; both sites presenting less lactobacilli than the left side samples. A distinct metabolomic signature associated with the physical separation of the uteri contributed to the differences in endometrial milieu.

CONCLUSIONS

Our study revealed that physical separation, among other factors in uterus didelphys, affects the endometrial microbiome, metabolome, and inflammatory state, with significant microbiome variation observed between the uteri, although similar endometrial receptivity patterns were noted.

Development of a prognostic scoring system for predicting hospitalization duration in postpartum endometritis

BACKGROUND

We aim to identify risk factors contributing to extended rehospitalizations in patients diagnosed with postpartum endometritis requiring intravenous antibiotics.

METHODS

This retrospective cohort study examined postpartum endometritis patients readmitted for treatment from 2014 to 2022, comparing short (≤ 48 h) and prolonged hospitalization (> 48 h). Data included patient demographics, medical history, presentation parameters, vaginal examination findings, sonographic data, laboratory results, and details of the current labor to create a scoring system predicting prolonged hospitalization risk.

RESULTS

During the study, 270 women with postpartum endometritis were hospitalized. Among them, 61 (22.6%) had hospital stays ≤ 48 h, while 209 (77.4%) experienced hospitalization > 48 h. Upon readmission, compared to the group with short stays, patients in the > 48 h group exhibited significantly elevated heart rates (97.9 ± 18.3 vs. 89.7 ± 12.9 bpm; p < 0.002) and CRP levels (13.8 ± 9.8 mg/dL vs. 8.1 ± 7 mg/dL; p < 0.001), respectively. Ultrasound revealed higher rates of pelvic hematoma or abscess in the > 48 h group (35.4% vs. 13.1%, respectively; p = 0.02). Multivariable logistic regression identified independent associations between hospitalization > 48 h and rupture of membranes > 14.5 h adjusted odds ratio (aOR 1.29, 95% CI 0.16-0.6, p = 0.016), temperature > 37.25 °C at readmission (aOR 1.31, 95% CI 0.013-0.42, p < 0.001), and CRP > 6.5 mg/dL at readmission (aOR 1.27, 95% CI 0.09-0.4, p = 0.002). A predictive scoring system was developed, indicating risks for prolonged hospitalization from 0.5 to 0.8.

CONCLUSION

The scoring system developed to predict prolonged hospitalization in postpartum endometritis can provide clinicians with valuable insights for improved diagnosis and prognosis.

Enhancing IVF Success in Challenging Infertility Cases: The Role of PRGF, GH, and Endometrial Optimization

Infertility in patients with reduced ovarian reserve and thin endometrial lining continues to pose a great challenge for successful in vitro fertilization. In the present case, a patient with a thin endometrium and low ovarian reserve resulted in a positive pregnancy with a specific IVF treatment plan. It included plasma-rich growth factors, growth hormone, supplementation along with some interventional support of endometrial scratching, and assisted hatching. Endometrial scratching and assisted hatching further optimized implantation potential. The use of these interventions hence promoted successful implantation of the embryo that contributed to positive pregnancy outcome and the birth of a healthy baby at 39 weeks. This case showed how individual ongoing comprehensive treatments definitively made a huge difference in the success of reproductive medicine.

Causal association of immune cells and endometritis: a Mendelian randomization study

Research exploring the link between immune cell profiles and the development of endometritis remains scant. This gap necessitates further study to decode the complex interrelations influencing this condition. In this analysis, we leveraged two-sample Mendelian randomization to examine the causal ties between the phenotypes of immune cells and the incidence of endometritis. Our evaluation hinged on data from 3757 participants hailing from Sardinia, focusing on a diverse array of 731 immune phenotypes, and cross-referenced with endometritis data sourced from the UK Biobank. To ensure rigor, we performed sensitivity analyses, utilized MR-Egger and MR-Presso to check for pleiotropy, and applied Cochran's Q test for assessing the heterogeneity of our findings. Our investigation identified numerous immune characteristics associated with endometritis. For certain immune traits, a lower risk of endometritis was observed, including: Absolute Counts of CD39 + CD4 + T cells, CD25 + CD39 + CD4 regulatory T cells, and CD25 + + CD8 + T cells; Absolute Counts of Switched Memory B cells; CD19 expression on IgD + CD38dim and Switched Memory B cells; CD20 expression on IgD + CD38- Unswitched Memory B cells; percentage of Switched Memory B cells among lymphocytes; CD16-CD56 expression on HLA DR + Natural Killer cells; percentage of CD11c + CD62L- monocytes; CD86 expression on monocytes; CCR2 expression on CD14 + CD16 + monocytes; and CD14 expression on Monocytic Myeloid-Derived Suppressor Cells, with Odds Ratios (ORs) between 0.413 and 0.703. On the contrary, increased risks of endometritis were linked with: the percentage of Effector Memory CD4 + T cells within the CD4 + T cell population; percentages of HLA DR + T cells and HLA DR + CD8 + T cells among T cells; CD4 expression on CD28 + CD4 + T cells; CD20 expression on CD20- CD38- B cells; percentage of IgD + CD24 + B cells within the B cell population; CD62L expression on CD62L + myeloid Dendritic Cells; and Absolute Counts of Plasmacytoid Dendritic Cells, with ORs from 1.473 to 2.677, indicating these traits potentially elevate the risk of developing endometritis. Our research delineates distinct causal links between specific immune cell phenotypes and endometritis, offering new perspectives that could contribute to the pinpointing of new therapeutic avenues for this condition.

Evaluating the clinical utility of cervical cultures in postpartum endometritis management

PURPOSE

To evaluate the utility of cervical cultures in the diagnosis and management of postpartum endometritis.

METHODS

A retrospective study was conducted on 1069 cervical cultures collected from postpartum women with suspected endometritis between 2011 and 2021. Patient demographics, obstetric history, clinical parameters, and culture results were analyzed. Microorganisms were categorized into five groups based on species and virulence. Statistical analysis was performed to identify associations between risk factors, pathogens, and disease severity.

RESULTS

The positivity rate for distinct microorganisms in cervical cultures was 33.1%. Escherichia coli (10.8%) and Group B Streptococcus (7.5%) were the most common isolates. Prolonged labor duration and prolonged rupture of membranes were associated with Enterobacterales infections. Elevated white blood cell count was linked to Enterobacterales and beta-hemolytic Streptococci, while the former were also associated with higher rate of postpartum clinic visit. No significant differences in disease severity were found between other microorganism groups.

CONCLUSION

The study suggests that while cervical cultures can identify potential pathogens in postpartum endometritis, their clinical utility is questionable due to the polymicrobial nature of the disease and the isolation of commensal microorganisms. The lack of significant differences in disease severity across various microorganism groups raises questions regarding the contribution of distinct bacterial identification in endometritis management.

The role and challenges of regulating endometrial microbiome in uterine health and diseases

The uterine environment provides necessary conditions for the existence of endometrial microbiota, which in turn plays an important role in maintaining the homeostasis of the uterine environment. The endometrial microbiome is highly susceptible to external factors such as age, hormones, menstrual, pregnancy, etc. When the microbiota is imbalanced, it will further promote the occurrence of uterine diseases such as endometritis and endometrial cancer. Regulating the microbiome of the endometrium is of positive significance for promoting uterine health. Among them, antibiotics, probiotics, prebiotics, and microbial transplantation may be important pathways for regulating endometrial microbiota in the future. However, there is currently no unified plan for evaluating the endometrial microbiota. In addition, due to the small sample size, it is easy to be contaminated by exogenous bacterial DNA, which poses great challenges for studying the mechanism of microbial community regulating uterine health. Therefore, there are still many areas worth exploring for the future of endometrial microbiome.

Clinicopathological Aspects of Dilation and Curettage (D&C) Biopsies Taken from Patients Living at High Altitude in Taif, KSA, with a Special Emphasis on Chronic Endometritis

BACKGROUND

Chronic endometritis (CE) is a persistent inflammation of the uterine lining. Although it has a minimal clinical presentation, CE adversely affects the reproductive ability of women. The aims of this study were to detect pathological endometrial patterns in D&C biopsies and to evaluate chronic endometritis in patients living in a high-altitude area (1800 m above sea level) in order to determine the clinical pathological features and prevalence.

MATERIALS AND METHODS

A cross-sectional study conducted at King Faisal Maternity Hospital included 100 samples of D&C biopsies from women complaining of various gynecological symptoms not due to gestational causes. The biopsies underwent tissue processing, H&E staining, and CD138 detection. Blood samples were taken for serological detection of infectious diseases, complete blood count, and chemical parameters.

RESULTS

The mean age of women in the study with CE was 48.5 ± 8.5 years, and that of those without CE was 46.9 ± 9.7 years. The most common complaints were abnormal uterine bleeding, accounting for 83%. CE was present in 8% of cases, and there was a nonsignificant difference in hematological parameters between women with CE and those with other pathological diagnoses. There were also nonsignificant differences in chemical parameters, except for FSH and LH levels, which showed a significant difference, with p-values of 0.05 and 0.02, respectively. It can be concluded that the most common gynecological complaint of women in this study was abnormal uterine bleeding.

CONCLUSIONS

The most commonly diagnosed pathological endometrial disorder in D&C biopsies was disordered proliferative endometrium, followed by endometrial polyps and endometrial hyperplasia. All of these are usually associated with hormonal disturbance, which appeared to be very common in the women in this study. The prevalence of chronic endometritis detected in our study was 8%, which is relatively high.

Chronic endometritis and recurrent reproductive failure: a systematic review and meta-analysis

Background

The endometrium holds a crucial role in reproduction by supporting blastocyst adhesion, cytotrophoblast invasion and fetal development. Among the various uterine disorders, endometritis, particularly chronic endometritis (CE), has gained attention due to its association with adverse reproductive outcomes (recurrent pregnancy loss (RPL), recurrent implantation failure (RIF), and infertility). The association between CE and adverse reproductive outcomes stresses the necessity for comprehensive diagnostic and therapeutic strategies to optimize fertility outcomes and support individuals in their journey towards parenthood.

Aim

To explore the relationship between CE and reproductive disorders.

Methods

Following PRISMA guidelines, a systematic review and meta-analysis using published data from 1990 to 2024 were carried out.

Results

A population of 1,038 women was included. Regarding CE-infertility association, a positive correlation was found, with 19.46% CE rate in infertile women compared to 7.7% in controls (OR: 2.96, 95% CI 1.53-5.72, p 0.001). No significant association was observed between RIF and CE (OR: 1.10, 95% CI 0.26-4.61, p 0.90), CE rates in both groups were relatively comparable, with 6.35% in women with RIF and 5.8% in controls. On the opposite, a strong association between CE and RPL was found, reporting a CE rate of 37.6% in RPL cases compared to 16.4% in controls (OR: 3.59, 95% CI 2.46-5.24, p < 0.00001).

Conclusions

CE appears to be associated to infertility and RPL, while no significant association was noted in cases of RIF.

Systematic review registration

https://www.crd.york.ac.uk/prospero/#recordDetails PROSPERO, identifier CRD42024541879.

Revolutionizing chronic endometritis diagnosis: real-time polymerase chain reaction unveils microbial pathogens in Indian women with abnormal bleeding and reproductive challenges

Background

This study aimed to assess the utility of real-time-polymerase chain reaction (PCR) for diagnosing chronic endometritis (CE) by targeting 11 prevalent pathogens and to compare the outcomes with conventional culture-based diagnosis.

Study Design

A retrospective analysis was conducted on 500 patients with clinical conditions such as abnormal bleeding, in vitro fertilization failure, recurrent implantation failure, recurrent miscarriage, and recurrent pregnancy loss. The prevalence of 11 key pathogens associated with CE was evaluated in endometrial biopsy samples.

Results

In our study, PCR identified 318 cases (63.6%) positive for at least one of the 11 investigated pathogens, while culture-based methods detected 115 cases (23%). Predominant pathogens detected by PCR included Enterococcus faecalis (E. faecalis) (19%), Escherichia coli (E. coli) (6.8%), Staphylococcus aureus (S. aureus) (9%), Mycoplasma hominis (5%), Mycoplasma genitalium (6.2%), Streptococcus agalactiae (S. agalactiae) (4.2%), Ureaplasma urealyticum (4%), nontuberculous Mycobacterium (5.2%), Mycobacterium tuberculosis (1.2%), Neisseria gonorrhoeae (0.6%), and Chlamydia trachomatis (2.4%). Standard culture methods identified E. faecalis (10.8%), S. aureus (6.2%), E. coli (3.8%), and S. agalactiae (2.2%).

Conclusion

The DICE panel proves itself as a swift, precise, and cost-effective diagnostic tool for detecting both culturable and nonculturable endometrial pathogens in CE. Demonstrating superiority, the Molecular method outshines microbial culture, ensuring accurate and sensitive detection of CE-associated pathogens, harmonizing seamlessly with histology and hysteroscopy findings.

Leonurine: a comprehensive review of pharmacokinetics, pharmacodynamics, and toxicology

Leonurine is an alkaloid unique to the Leonurus genus, which has many biological activities, such as uterine contraction, anti-inflammation, anti-oxidation, regulation of cell apoptosis, anti-tumor, angiogenesis, anti-platelet aggregation, and inhibition of vasoconstriction. This paper summarizes the extraction methods, synthetic pathways, biosynthetic mechanisms, pharmacokinetic properties, pharmacological effects in various diseases, toxicology, and clinical trials of leonurine. To facilitate a successful transition into clinical application, intensified efforts are required in several key areas: structural modifications of leonurine to optimize its properties, comprehensive pharmacokinetic assessments to understand its behavior within the body, thorough mechanistic studies to elucidate how it works at the molecular level, rigorous safety evaluations and toxicological investigations to ensure patient wellbeing, and meticulously conducted clinical trials to validate its efficacy and safety profile.

Alloferon Mitigates LPS-Induced Endometritis by Attenuating the NLRP3/CASP1/IL-1β/IL-18 Signaling Cascade

Endometritis is an inflammatory reaction of the uterine lining that can lead to infertility. Alloferon, a linear non-glycosylated oligopeptide, has been recognized for its potent anti-inflammatory and immunomodulatory effects. In light of these attributes, this study aims to explore the potential therapeutic effects of alloferon in alleviating endometrial inflammation induced by lipopolysaccharide (LPS), while elucidating the underlying protective mechanisms. Two conditions representing pre- and post-menopause states were simulated using an ovariectomized (Ovx) murine model. The findings underscore alloferon's remarkable capacity to alleviate cardinal signs of endometritis, including redness, swelling, and congestion, while concurrently restoring the structural integrity of the endometrial tissue. Moreover, alloferon effectively modulates the expression of key inflammatory mediators, such as nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3), cysteine aspartate-specific protease 1 (CASP1), interleukin-1β (IL-1β), and interleukin-18 (IL-18). In vitro experiments were conducted to further corroborate and validate these findings. In conclusion, alloferon shows promising potential in mitigating LPS-induced inflammation by attenuating the NLRP3/CASP1/IL-1β/IL-18 signaling cascade.

Lack of Annexin A1 Exacerbates Inflammatory Response in Acute Endometritis Model

Annexin A1 (AnxA1) is a glucocorticoid-inducible protein and an important endogenous modulator of inflammation. However, its effect in the endometrial microenvironment is poorly explained. This study aimed to evaluate the role of endogenous AnxA1 in an endometritis mouse model induced by lipopolysaccharide (LPS). Female C57BL/6 wild-type (WT) and AnxA1-/- mice were divided into two groups: SHAM and LPS. To induce endometritis, mice received a vaginal infusion of 50 μL of LPS (1 mg/mL) dissolved in phosphate-buffered saline. After 24 h, the mice were euthanized, and blood and uteri samples were collected. The endometrium inflammatory scores were significantly increased in the LPS-treated group. AnxA1-/- mice from the LPS group demonstrated a significant increase in the number of degranulated mast cell levels compared to AnxA1-/- SHAM mice. The Western blotting analysis revealed that a lack of AnxA1 promoted the upregulation of NLRP3 and pro-IL-1β in the acute endometritis animal model compared to WT LPS animals. LPS-induced endometritis increased the number of blood peripheral leukocytes in both WT and AnxA1-/- mice compared with SHAM group mice (p < 0.001). AnxA1-/- mice also showed increased plasma levels of IL-1β (p < 0.01), IL-6, IL-10, IL-17, and TNF-α (p < 0.05) following LPS-induced endometritis. In conclusion, a lack of endogenous AnxA1 exacerbated the inflammatory response in an endometritis model via NLRP3 dysregulation, increased uterine mast cell activation, and plasma pro-inflammatory cytokine release.

Chronic endometritis and the endometrial microbiota: implications for reproductive success in patients with recurrent implantation failure

BACKGROUND

Chronic endometritis (CE) is associated with poor reproductive outcomes, yet the role of endometrial microbiota in patients with recurrent implantation failure (RIF) and CE remains unclear. This study aims to characterize endometrial microbiota in RIF patients with CE and assess its implications for reproductive outcomes.

METHODS

In this prospective study, we enrolled RIF patients both with and without CE. Endometrial and cervical samples were collected for 16 S rRNA gene sequencing. Microbiota composition was compared between groups using diversity indices, phylum, and genus-level analysis. Canonical correlation analysis (CCA) and Spearman's correlation coefficients were used to assess relationships between CE, reproductive outcomes, and microbiota. Predictive functional profiling was performed to evaluate metabolic pathways associated with CE.

RESULTS

Endometrial microbiota in CE patients exhibited greater diversity and evenness compared to non-CE patients. Principal coordinates analysis (PCoA) revealed distinct clustering between CE and non-CE groups. Linear discriminant analysis (LDA) identified Proteobacteria, Aminicenantales, and Chloroflexaceae as characteristic of CE, while Lactobacillus, Acinetobacter, Herbaspirillum, Ralstonia, Shewanela, and Micrococcaceae were associated with non-CE. CCA demonstrated associations between CE, adverse reproductive outcomes, and specific bacterial taxa. Microbial metabolic pathways significantly differed between CE and non-CE groups, with enrichment in pathways related to cofactors, vitamins, secondary metabolites, and the immune system in CE patients.

CONCLUSION

RIF patients with CE exhibit distinct endometrial microbiota compositions associated with adverse reproductive outcomes. The increased microbial diversity and altered metabolic pathways in CE suggest a potential correlation with reproductive outcomes, although further studies are necessary to elucidate the causal relationship between microbiota alterations and fertility. Modulating the endometrial microbiome may represent a novel therapeutic strategy to improve IVF outcomes in patients with CE.

Correlation between hysteroscopic features and specific microbial species in women with chronic endometritis

Objective and rationale

Chronic endometritis (CE) has recently been associated with unexplained infertility and recurrent miscarriages. The current gold standard for CE detection is histopathological examination. However, office hysteroscopy and endometrial cultures are also significant, due to the possible link between CE and various microorganisms. Bacterial colonization of the endometrium has been associated with reduced success rates of in vitro fertilisation embryo transfer. Few studies have tried to correlate CE hysteroscopy findings with pathogenic microorganisms. This prospective cohort study sought to establish whether hysteroscopic diagnostic lesions correlate with specific microbial species.

Methods

The study encompassed women undergoing diagnostic tests for a range of subfertility health issues. 189 women completed the standard office diagnostic hysteroscopy (DH). 181 had also endometrial samples taken for microbial culture investigation. Correlation analysis (χ2 and Fisher's exact test) between hysteroscopic findings suggestive of CE and endometrial cultures was carried out. Logistic regression models were also fitted to measure whether a positive endometrial culture could affect CE conditions.

Results

A significant association of E. coli was observed between the hysteroscopically characterized CE + group with focal hyperplasia, when compared to the non-CE group. Logistic regression analysis revealed that women positive for E. coli were 4.423 times more likely to have focal endometrial hyperplasia. No other significant correlations were identified between DH and positive endometrial cultures.

Conclusions

The presence of E. coli in the endometrium was significantly correlated with focal hyperplasia findings from hysteroscopy, emphasizing the importance of microbial cultures in the diagnosis and targeted treatment of CE in women with subfertility.

Hysteroscopic features suggestive of chronic endometritis: a systematic review

The purpose of this systematic review is to identify common hysteroscopic findings suggestive of endometritis, chronic or subclinical, based on current scientific evidence. Data sources were MEDLINE, Embase, PubMed and other sources of grey literature. Four (4) authors independently selected studies addressing hysteroscopic detection of CE based on specific and clearly stated hysteroscopic criteria. The diagnosis was confirmed by histologic assessment, as stated in the materials and methods of these studies included. The initial search identified 599 studies, of which 21 met the inclusion criteria. Significant heterogeneity among published studies on Chronic endometritis (CE) remains the main limitation in performing a metanalysis and further analysis of diagnostic accuracy on the subject. Hysteroscopy is an important diagnostic tool in cases of chronic endometritis when accompanied by endometrial biopsies. Clinicians relate hyperaemia and endometrial oedema with chronic endometritis while more than half include micropolyposis as a pathognomonic feature of this subclinical condition. Micropolyps, stromal oedema, haemorrhagic spots, strawberry aspect, and hyperaemia are proposed as adequate indicators of hysteroscopic evidence of CE according to the literature. The impact of CE in long-term reproductive outcomes remain unclear, thus clinicians ought to communicate this to the patients and provide treatment where clinically appropriate. In addition, we present hysteroscopic images of histologically confirmed CE cases that could play the role of a hysteroscopic atlas.

Chronic endometritis incidence in infertile women with and without polycystic ovary syndrome: a propensity score matched study

BACKGROUND

Polycystic ovary syndrome (PCOS) is known to be associated with chronic low-grade inflammation and endometrial dysfunction. Chronic endometritis (CE) is a type of local inflammation that can contribute to endometrial dysfunction in infertile women. Some clinicians recommend screening for CE in women at high risk, such as those with endometrial polyps. However, it is still uncertain whether there is a relationship between PCOS and CE, as well as whether women with PCOS require enhanced screening for CE. This study was to assess the incidence of CE among infertile women with PCOS by hysteroscopy combined with histopathology CD138 immunohistochemical staining of endometrium.

METHODS

A total of 205 patients in the PCOS group and 4021 patients in the non-PCOS group from July 2017 to August 2022 were included in this retrospective study. After nearest-neighbor 1:4 propensity score matching (PSM), 189 PCOS patients were matched with 697 non-PCOS patients. Basic information was recorded. The CE incidence was compared. The risk factors affecting CE incidence were also analyzed.

RESULTS

No significantly higher CE incidence in infertile women with PCOS were found either in total analysis or after PSM (P = 0.969; P = 0.697; respectively). Similar results were discovered in the subgroup of Body Mass Index (BMI) (P = 0.301; P = 0.671; P = 0.427; respectively) as well as the four PCOS phenotypes (P = 0.157). Intriguingly, the incidence of CE increased as BMI increased in the PCOS group, even though no significant differences were found (P = 0.263). Multivariate logistic regression showed that age, infertility duration, infertility type, PCOS, and obesity were not the independent risk factors affecting CE incidence.

CONCLUSION

The incidence of CE in PCOS patients did not significantly increase compared to non-PCOS patients. Similarly, no significant differences in the incidence of CE were observed among different PCOS phenotypes. The current evidence does not substantiate the need for widespread CE screening among PCOS women, potentially mitigating the undue financial and emotional strain associated with such screenings.

Retained Intrauterine Fetal Bone Fragments Causing Secondary Infertility: A Review

Retained intrauterine fetal bone fragments are emerging as a potential yet often overlooked cause of secondary infertility, posing significant challenges for couples who have previously experienced successful pregnancies. This review article explores the association between retained fetal bone fragments and secondary infertility by delving into their impact on fertility, pregnancy outcomes, and diagnostic challenges. The review highlights the underlying mechanisms of fragment retention, including immune response and inflammation, and their detrimental effects on endometrial receptivity and implantation. The diagnostic difficulties and importance of specialized imaging techniques like hysteroscopy for accurate diagnosis are also discussed. The article also provides insights into available treatment options, such as medical management and surgical interventions, focusing on hysteroscopy as the gold standard for diagnosis and treatment. The implications for clinical practice emphasize early diagnosis and intervention to improve fertility outcomes and reduce the emotional burden of secondary infertility. Furthermore, the review discusses preventive strategies and the potential for future research to refine diagnostic methods and explore novel treatments. By recognizing and addressing the impact of retained fetal bone fragments, this review aims to enhance the understanding and management of this condition, providing valuable support to couples seeking to overcome the challenges of secondary infertility on their journey toward parenthood.

Endometriosis and infertility: the hidden link between endometritis, hormonal imbalances and immune dysfunctions preventing implantation!

Endometriosis is a chronic inflammatory condition affecting up to 10% of women of reproductive age and this, depending on its severity, very often leads to infertility. New research has shed light on the role of underlying endometritis due to the presence of inflammatory, non-oestrogen metabolising microbiome at the mucosal interface and this in turn leads to the activation of aggressive, non-tolerant immune cells in the endometrium. These immune cells require the presence of tolerance-inducing commensals such as Lactobacilli so as to allow the implantation of the fertilised egg. New therapies should be holistic and address both the dysbiosis as well as immune abnormalities. Routine immune monitoring of the immune cells derived from the endometrium and/or microbial profiling should recommended to better predict assisted reproduction outcomes in these couples.

Effect of the decision to perform hysteroscopy on asymptomatic patients before undergoing assisted reproduction technologies-a systematic review and meta-analysis

OBJECTIVE

Routine hysteroscopic evaluation before assisted reproductive technology treatment is a novel approach with the potential to reduce assisted reproductive technology failure even in the absence of evidence of uterine pathology. Following the publication of several relatively high-quality trials on this topic, we sought to determine if this practice is beneficial.

DATA SOURCES

We searched Web of Science, MEDLINE, PubMed, Scopus, Cochrane Library, and ClinicalTrials.gov from each database's inception until May 31, 2022 with our search strategy, attempting to locate all randomized controlled trials assessing the use of hysteroscopy in otherwise asymptomatic women undergoing assisted reproductive technology.

STUDY ELIGIBILITY CRITERIA

We included only randomized controlled trials that included at least one of our selected outcomes, and we excluded any studies with suspicion of pathology before the time of hysteroscopy, other than knowledge of the patient's infertility. We included all the aforementioned studies regardless of procedures or modifications performed as a result of hysteroscopic findings. Our initial search yielded 1802 results, which were reduced to 1421 after removal of duplicates. Ultimately, 11 studies were found to meet our criteria and were included in our quantitative synthesis.

METHODS

We used ReviewManager software, version 5.4.1 to analyze the data, which we imported after manually gathering from the 11 studies. Continuous and dichotomous outcomes were imported as standard deviations. Pooled analysis was described as a mean difference, relative to 95 % confidence interval in cases of continuous data. Dichotomous outcomes were analyzed using risk ratios and 95% confidence intervals. In homogeneous outcomes, we used a fixed-effects model, and in heterogeneous outcomes we used a random-effects model.

RESULTS

Our results showed that hysteroscopy was associated with significant improvement in the clinical pregnancy rate (risk ratio, 1.27 [1.11-1.45]; P<.001). We found no differences between the hysteroscopy group and the control group in live birth rate (risk ratio, 1.26 [0.99-1.59]; P=.06), miscarriage rate (risk ratio, 0.99 [0.81-1.19]; P=.88), fertilization rate (risk ratio, 1.01 [0.93-1.09]; P=.88), incidence of multiple gestations (risk ratio, 1.29 [0.98-1.71]; P=.07), number of embryos transferred (mean difference, 0.04 [-0.18 to 0.26]; P=.73), chemical pregnancy rate (risk ratio, 1.01 [0.86-1.17]; P=.93), and number of oocytes retrieved (mean difference, 0.44 [-0.11 to 0.98]; P=.11).

CONCLUSION

We observed an improvement in the clinical pregnancy rate, but no significant improvement in the live birth rate with routine hysteroscopy before assisted reproductive technology treatment. We believe this does not represent sufficient evidence to recommend routine hysteroscopy for otherwise asymptomatic patients before assisted reproductive technology treatment at this time.

Effectiveness of chlamydia Test and Treat strategy in preventing adverse pregnancy outcomes: protocol for a randomized controlled trial

Introduction

Chlamydia trachomatis is one of the most common bacterial sexually transmitted infections worldwide, and is associated with an increased risk of adverse pregnancy outcomes. However, whether providing chlamydia screening and treatment during the first trimester of pregnancy could reduce adverse pregnancy outcomes is still not clear. This study reports a randomized controlled trial (RCT) protocol to evaluate the effectiveness of chlamydia Test and Treat during early pregnancy in preventing adverse pregnancy outcomes in China.

Methods and analysis

This trial is a multi-center two-arm RCT targeting 7,500 pregnant women in early pregnancy (6-20 weeks). The inclusion criteria included: 18-39 years old, on their first antenatal visit, in the first trimester, and plan to deliver in the study cities. Following a block randomization procedure, every block of twenty women will be randomly assigned in a 1:1 ratio into two arms: (1) a Test and Treat arm in which women receive free chlamydia testing immediately after enrollment and people tested as chlamydia positive will receive standardized treatment and partner treatment; (2) a control arm in which women receive regular prenatal care without receiving testing during the pregnancy period, but collect urine samples and test them after delivery or indicating a chlamydia-related complication during pregnancy happens. The primary outcome is a composite of eight adverse events rate at delivery between two arms, including stillbirth, infant death, spontaneous abortion, preterm labor, low birth weight, premature rupture of membranes, postpartum endometritis, and ectopic pregnancy. Secondary outcomes include the cost-effectiveness of the intervention, the proportion of people tested with chlamydia infection, the proportion of tested-positive patients that received treatment, and the proportion of people who were cured 1 month after the treatment initiation. Urine specimens will be collected and tested for chlamydia by using Nucleic Acid Amplification Test. Data will be analyzed according to the intention-to-treat principle.

Discussion

This trial will test the hypothesis that early testing and treating of chlamydia can reduce the risk for adverse pregnancy outcomes and may help in developing chlamydia screening guidelines in China and other countries with a similar prevalence of chlamydia infection.

Trial registration

Chinese Clinical Trials Registry, ChiCTR2000031549. Registered on April 4, 2020.