Review: Chronic endometritis and its effect on reproduction

Inflammation-Related Molecules at the Maternal–Fetal Interface during Pregnancy and in Pathologically Altered Endometrium

The blastocyst expresses paternally derived alloantigens and induces inflammation during implantation. However, it is necessary for the onset of pregnancy. An abnormal response might result in a pathological course of pregnancy or pregnancy failure. On the other hand, a state of maternal immune tolerance is necessary to ensure the normal development of pregnancy by suppressing inflammatory processes. This article discusses recognized mechanisms and the significance of inflammatory processes for embryo implantation and pregnancy establishment. We would also like to present disorders involving excessive inflammatory response and their influence on events occurring during embryo implantation. The chain of correlation between the processes responsible for embryo implantation and the subsequent physiological course of pregnancy is complicated. Many of those interrelationships are still yet to be discovered. Undoubtedly, their recognition will give hope to infertile couples for the emergence of new treatments that will increase the chance of giving birth to a healthy child.

“Iron triangle” of regulating the uterine microecology: Endometrial microbiota, immunity and endometrium

The uterus is the core place for breeding new life. The balance and imbalance of uterine microecology can directly affect or even dominate the female reproductive health. Emerging data demonstrate that endometrial microbiota, endometrium and immunity play an irreplaceable role in regulating uterine microecology, forming a dynamic iron triangle relationship. Up to nowadays, it remains unclear how the three factors affect and interact with each other, which is also a frontier topic in the emerging field of reproductive tract microecology. From this new perspective, we aim to clarify the relationship and mechanism of the interaction of these three factors, especially their pairwise interactions. Finally, the limitations and future perspectives of the current studies are summarized. In general, these three factors have a dynamic relationship of mutual dependence, promotion and restriction under the physiological or pathological conditions of uterus, among which the regulatory mechanism of microbiota and immunity plays a role of bridge. These findings can provide new insights and measures for the regulation of uterine microecology, the prevention and treatment of endometrial diseases, and the further multi-disciplinary integration between microbiology, immunology and reproductive medicine.

Baogong decoction treats endometritis in mice by regulating uterine microbiota structure and metabolites

Endometritis is persistent inflammation caused by bacteria, which can lead to infertility. Although traditional Chinese medicine (TCM) has been used to treat endometritis, the underlying mechanism is still unclear. Here, Baogong Decoction (BGD), a TCM compound, was used to treat mouse endometritis induced by Escherichia coli (E. coli), and then 16S rRNA sequencing and non-targeted metabolomics were used to investigate the change of uterine microbiota and metabolomes in serum and uterine after BGD treatment. Finally, the therapeutic effect of potential metabolites for treating mouse endometritis screened by combined omics analyses was verified using pathological model. The results showed that BGD treatment could effectively treat endometritis associated with the increasing relative abundance of Firmicutes, Bacteroides, Lactobacillus and Lactococcus, and the decreasing relative abundance of Cupriavidus and Proteobacteria. 133 and 130 metabolites were found to be potential biomarkers in serum and uterine tissue respectively. In serum and tissues, dehydroepiandrosterone (DHEA) and catechol were significantly increased in the BGD treatment versus the inflammation group. Results of combined omics analyses demonstrated that DHEA was positively correlated with changes in microbiota. Results of pathological model demonstrated that DHEA could cure endometritis effectively associated with the decreasing infiltration of inflammatory cells and expression of inflammatory factors in the uterus. In summary, our results demonstrated that BGD could cure endometritis in mice by modulating the structure of the uterine microbiota and its metabolites, in which DHEA may be one of the main components of the therapeutic effect of BGD.

Does antibiotic therapy for chronic endometritis improve clinical outcomes of patients with recurrent implantation failure in subsequent IVF cycles? A systematic review and meta-analysis

PURPOSE

This study aims to assess whether antibiotic therapy for chronic endometritis (CE) could improve subsequent IVF outcomes in patients with recurrent implantation failure (RIF).

METHODS

Studies that explore CE treatment in patients with RIF were retrieved from PubMed, EMBASE, Wanfang, and Google Scholar up to Jan 31, 2022. All retrieved studies were selected according to the inclusion and exclusion criteria. The main outcome measures include implantation rate (IR), clinical pregnancy rate (CPR), ongoing pregnancy rate/live birth rate (OPR/LBR), and miscarriage rate (MR). Odds ratios (ORs) were analyzed for pregnancy outcomes with a 95% confidence interval (CI).

RESULTS

Nine articles were enrolled in this study. Patients receiving oral antibiotic administration (OAA) did not show any advantage over patients without CE with regard to IR, OPR/LBR, and MR, but they showed a higher CPR. Patients with cured CE after OAA therapy had significantly higher CPR, IR, and OPR/LBR compared with patients without CE. Patients with persistent CE after OAA therapy had significantly lower IR, CPR, and OPR/LBR compared with patients without CE. Patients with cured CE had significantly higher IR, CPR, and OPR/LBR compared with persistent CE patients.

CONCLUSIONS

Antibiotic treatment may improve the pregnancy outcomes of RIF patients in subsequent IVF cycles only if the condition of CE is confirmed cured in a control biopsy afterwards. Otherwise, no sufficient evidence has shown improvements in clinical outcomes in RIF patients with persistent CE.

Granulocyte-macrophage colony-stimulating factor-containing medium treatment after thawing improves blastocyst-transfer outcomes in the frozen- thawed blastocyst-transfer cycle

PURPOSE

To determine whether granulocyte-macrophage colony-stimulating factor (GM-CSF)-containing medium could improve embryo-transfer outcomes in frozen-thawed blastocyst transfer.

METHODS

Patients who underwent frozen-thawed blastocyst transfer (430 women, aged 30-39 years, 566 cycles) were analyzed. Frozen-thawed blastocysts were cultured in GM-CSF-containing medium or control medium for 3-5 h, followed by transfer to the uterus. The embryo-transfer outcomes in the two groups were measured and compared, and a propensity score matching (1:1) method was used to balance the differences in baseline characteristics. We analyzed 213 matched samples.

RESULTS

In patients who underwent frozen-thawed blastocyst transfer with GM-CSF, the percentage of human chorionic gonadotropin-positive cases, biochemical pregnancies, clinical pregnancies, ongoing pregnancies, and live birth rates was 60.6%, 7.98%, 52.6%, 42.9%, and 40.9%, respectively, as compared with 45.1%, 3.29%, 41.8%, 31.1%, and 30.5%, respectively, for the control groups. The rates of human chorionic gonadotropin positivity (odds ratio [OR]: 1.87, 95% confidence interval: [CI]: 1.27-2.75), biochemical pregnancy (2.55, 1.04-6.29), clinical pregnancy (1.54, 1.05-2.27), ongoing pregnancy (1.64, 1.13-2.41), and live birth (1.67, 1.14-2.45) were significantly higher in the GM-CSF group than the control group. The incidence of pregnancy loss (22.3% vs. 27.0%) did not significantly differ between the groups.

CONCLUSION

The use of a GM-CSF-containing medium for blastocyst-recovery culture improved the live birth rate as a result of increased implantation rate in the frozen-thawed blastocyst-transfer cycle. The use of GM-CSF-containing medium following blastocyst thawing could be an effective choice for improving the blastocyst-transfer outcomes.

Endometrial polyp is associated with a higher prevalence of chronic endometritis in infertile women

OBJECTIVE

To assess the prevalence of chronic endometritis (CE) among infertile women with endometrial polyps (EP).

METHODS

From June 2017 to October 2021, 583 patients in the polyp group (group A-group A1: single-polyp group, 322 patients; group A2: multiple-polyp group, 261 patients) and 4534 patients in the non-polyp group (group B) were included in this retrospective study. Hysteroscopic polypectomy was performed in group A. Endometrial biopsy and CD138 immunohistochemistry staining for specimens was carried out in all groups.

RESULTS

Prevalence of CE was significantly higher in group A than in group B (45.28% vs. 27.94%, P < 0.001). A significantly higher prevalence of CE was found in group A1 and group A2 compared with group B (42.24% vs. 27.94%, P < 0.001; 49.04% vs. 27.94%, P < 0.001; respectively). No significant difference in the comparison of CE prevalence was found between group A1 and group A2. Similar results were achieved in the subgroup analysis among patients aged 40 years or older and patients younger than 40 years.

CONCLUSION

EP, either single EP or multiple EP, positively correlates with CE. The prevalence of CE was similar between the single-polyp group and the multiple-polyp group.

Upstream stimulatory factor 2 (USF2) induced upregulation of triggering receptor expressed on myeloid cells 1 (TREM1) promotes endometritis by regulating toll-like receptor (TLR) 2/4-nuclear factor-kappaB (NF-κB) signaling pathway

Triggering receptor expressed on myeloid cells 1 (TREM1) participates in the development of endometritis. This study aims at identifying the effects and interaction of TREM1 and upstream stimulatory factor 2 (USF2) in endometritis by using a model of lipopolysaccharide (LPS)-induced human endometrial epithelial cells (HEnEpCs). ELISA was performed to determine the levels of interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF-α) after LPS stimulation. TREM1 and USF2 expression was examined with RT-qPCR and Western blot. The JASPAR database was employed to predict the binding site between USF2 and TREM1, which was confirmed by luciferase reporter and chromatin immunoprecipitation assays. After TREM1 overexpression, IL-6, IL-1β, and TNF-α expression was detected by ELISA. Next, the binding of TREM1 to toll-like receptor (TLR) 2/4 was examined with co-immunoprecipitation. Then, proteins in TLR2/4-nuclear factor-kappaB (NF-κB) signaling in HEnEpCs under LPS condition were assessed by Western blot or immunofluorescence before and after TREM1 knockdown. Finally, TLR2 or TLR4 was silenced to explore whether intervene TLR2/4-NF-κB signaling pathway could rescue TREM1-overexpression-induced inflammation in LPS-induced HEnEpCs. Results revealed that upregulated TREM1 was observed in LPS-challenged HEnEpCs. Next, USF2 was found to have transcriptionally active TREM1 expression. Additionally, USF2 knockdown decreased the levels of IL-6, IL-1β, and TNF-α, whereas this effect was rescued after TREM1 overexpression. Besides, TREM1 could bind to TLR2/4 to regulate NF-κB signaling. Moreover, the intervention of TLR2/4-NF-κB signaling pathway rescued TREM1-overexpression-induced inflammation in LPS-stimulated HEnEpCs. Collectively, USF2 promotes endometritis by upregulating TREM1, thereby activating TLR2/4-NF-κB pathway.

The association between chronic deciduitis and preeclampsia

Chronic deciduitis (CD) is slight inflammation of the decidua found during pregnancy. The cause of preeclampsia is thought to be placental hypoplasia, and various theories have been proposed to explain the detailed mechanism; however, its association with decidual inflammation is unclear. A retrospective case control study was conducted in a single university. Subjects were cases who delivered by cesarean section between January 1, 2013 and June 30, 2020 and whose placentas were pathological assessed. CD was diagnosed by CD138 immunostaining of placental decidua tissue, and the perinatal prognosis and incidences of hypertensive disorder of pregnancy and preeclmpsia were examined according to the presence or absence of CD. A logistic regression analysis was performed to evaluate the association between preeclampsia and 11 explanatory variables (10 patient or perinatal background factors and CD). The study population included 76 patients (non-CD, n = 54; CD, n = 22). The rate of preeclampsia was significantly higher in the CD group (P = 0.0006). Patients with CD gave birth at a significantly earlier gestational age (P=0.040) with a lower birth weight (P = 0.001), and a higher rate of LFD (P = 0.005). The Apgar scores at 1 and 5 min and umbilical artery pH were lower (P = 0.0003, 0.021 and 0.002, respectively) in the CD group. The logistic regression analysis revealed that CD was positively associated with preeclampsia. A retrospective examination of the placenta found that patients with CD had a significantly higher incidence of preeclampsia and CD is considered to be a factor that is associated with poor perinatal outcomes.

MUM-1 immunohistochemistry has high accuracy and reliability in the diagnosis of chronic endometritis: a multi-centre comparative study with CD-138 immunostaining

PURPOSE

The current gold standard for chronic endometritis (CE) diagnosis is immunohistochemistry (IHC) for CD-138. However, IHC for CD-138 is not exempt from diagnostic limitations. The aim of our study was to evaluate the reliability and accuracy of MUM-1 IHC, as compared with CD-138.

METHODS

This is a multi-centre, retrospective, observational study, which included three tertiary hysteroscopic centres in university teaching hospitals. One hundred ninety-three consecutive women of reproductive age were referred to our hysteroscopy services due to infertility, recurrent miscarriage, abnormal uterine bleeding, endometrial polyps or myomas. All women underwent hysteroscopy plus endometrial biopsy. Endometrial samples were analysed through histology, CD138 and MUM-1 IHC. The primary outcome was to evaluate the diagnostic accuracy of MUM-1 IHC for CE, as compared with CD-138 IHC.

RESULTS

Sensitivity and specificity of CD-138 and MUM-1 IHC were respectively 89.13%, 79.59% versus 93.48% and 85.03%. The overall diagnostic accuracy of MUM-1 and CD-138 IHC were similar (AUC = 0.893 vs AUC = 0.844). The intercorrelation coefficient for single measurements was high between the two techniques (ICC = 0.831, 0.761-0.881 95%CI). However, among CE positive women, MUM-1 allowed the identification of higher number of plasma cells/hpf than CD-138 (6.50 [SD 4.80] vs 5.05 [SD 3.37]; p = 0.017). Additionally, MUM-1 showed a higher inter-observer agreement as compared to CD-138.

CONCLUSION

IHC for MUM-1 and CD-138 showed a similar accuracy for detecting endometrial stromal plasma cells. Notably, MUM-1 showed higher reliability in the paired comparison of the individual samples than CD-138. Thus, MUM-1 may represent a novel, promising add-on technique for the diagnosis of CE.

miR-424-5p overexpression inhibits LPS-stimulated inflammatory response in bovine endometrial epithelial cells by targeting IRAK2

Endometritis is inflammation of endometrium due to various factors and is a common cause of infertility. Several remedies used for endometritis like antibiotics, hormones, and herbs. Studies confirm that microRNAs play a significant role in various inflammatory diseases. However, the role of miR-424-5p in endometritis is not clear. In our study, histopathology, real-time quantitative polymerase chain reaction, Western blot analysis, immunofluorescence, ELISA, and dual-luciferase reporter assay were used to elucidate the effect of miR-424-5p in lipopolysaccharide (LPS)-primed inflammatory response in bovine endometrial epithelial cells (BEECs) and clarify the potential mechanism. Our results revealed that miR-424-5p mimics noticeably decrease the production of proinflammatory cytokines (IL-1β, IL-6, and TNF-α), while miR-424-5p inhibitors have inverse effects in BEECs. Moreover, overexpression of miR-424-5p on BEECs cells also suppressed NF-κB p65 activation. Afterwards, we verified that miR-424-5p inhibited Interleukin 1 Receptor Associated Kinase 2 (IRAK2) expression by binding to the 3'-UTR of IRAK2 mRNA. Further, co-transfection of miR-424-5p inhibitors and siRNA-IRAK2 revealed that negative regulation of miR-424-5p on LPS-induced inflammatory response in BEECs was mediated by IRAK2.Mutually, miR-424-5p pharmacologic stabilization represents an entirely unique medical aid for cow endometritis and other inflammation-related diseases.

Transcriptome study of receptive endometrium in overweight and obese women shows important expression differences in immune response and inflammatory pathways in women who do not conceive

Obesity and being overweight are growing worldwide health problems that also affect women of reproductive age. They impair women’s fertility and are associated with lower IVF success rates. The mechanism by which increased body weight disrupts fertility has not yet been established. One possibility is that it affects the process of embryo implantation on the endometrial level. The purpose of our study was to determine the differences in enriched biological pathways in the endometrium of overweight and obese women undergoing IVF procedures. For this purpose, 14 patients (5 pregnant, 9 non-pregnant) were included in the study. Endometrial samples were obtained during the window of implantation and RNA sequencing was performed. There were no differences in general patient’s and IVF cycle characteristics between pregnant and non-pregnant women. In the endometrial samples of women who did not conceive, pathways related to the immune response, inflammation, and reactive oxygen species production were over-expressed. Our findings show that the reason for implantation failure in overweight and obese women could lie in the excessive immune and inflammatory response at the endometrial level.

Histopathological evaluation of cesarean scar defect in women with cesarean scar syndrome

Purpose

To explore the histopathological findings of cesarean scar defect (CSD) and the immunological component in women with cesarean scar syndrome (CSS).

Methods

This retrospective study was conducted in a university hospital and a public hospital. A total of 63 patients with secondary infertility due to CSS who underwent laparoscopic resection of the CSD lesion were enrolled (CSS group), and 21 patients who underwent hysterectomy with a history of cesarean section were enrolled as control (non‐CSS group). We compared the differences in histopathological findings of CSD lesions by hematoxylin and eosin staining and immunohistochemistry for CD3, CD20, CD56, CD68, CD138, myeloperoxidase, and tryptase between the two groups.

Results

The frequency of presence of endometrium on the CSD surface was significantly lower (p = 0.0023) and that of adenomyosis was significantly higher (p = 0.0195) in the CSS group than in the non‐CSS group. The number of CD3‐, CD20‐, CD68‐, and tryptase‐positive cells was significantly lower in the CSS group than in the non‐CSS group; however, the number of CD138‐positive cells was significantly higher in the CSS group (p = 0.0042).

Conclusions

This study suggested that the absence of endometrium, presence of adenomyosis, and chronic inflammation in CSD contributes to secondary infertility due to CSS.

Human implantation: The complex interplay between endometrial receptivity, inflammation, and the microbiome

Human embryo implantation is an intricate spatiotemporal process that involves the intimate association between the embryo and the endometrium of the mother. During implantation, the endometrium undergoes a dynamic cascade of gene activation and repression, largely driven by autocrine, paracrine, and endocrine action. Steroid hormones, such as estrogen and progesterone, act on a variety of targets including cellular adhesion molecules (CAMs), cytokines, and growth factors to facilitate the implantation process. Given the synchrony required to achieve implantation, it is unsurprising that embryo implantation represents a substantial problem for infertility patients. This is due to a complex interplay taking place at the level of the endometrium. This review discusses the intricacies of embryo implantation including the window of implantation, the cyclical phases of the endometrium, the implantation process itself, and features of endometrial receptivity. Additionally, we will discuss new research regarding inflammatory reproductive biology, epigenetics and microRNA, and the role of the vaginal and endometrial microbiome in implantation. A better understanding of embryo implantation and the interactions occurring at the level of the blastocyst and the endometrium will improve patient care for infertile patients who experience this frustrating challenge.

Honokiol inhibits endoplasmic reticulum stress-associated lipopolysaccharide-induced inflammation and apoptosis in bovine endometrial epithelial cells

Honokiol (HKL) has been previously reported to exert anti-inflammatory effects in numerous diseases. However, the role of HKL in endometritis remains unclear. The present study aimed to explore and elucidate the role of HKL in a lipopolysaccharide (LPS)-induced in vitro model of endometritis. Bovine endometrial epithelial cells (bEECs) were pre-treated with HKL at doses of 1, 10 and 20 µM, followed by 1 µg/ml LPS. MTT assay was then used to detect cell viability. ELISA was utilized to measure the levels of the proinflammatory cytokines TNF-α, IL-1β and IL-6 in bEECs culture supernatants. Reverse transcription-quantitative PCR was further performed to examine the mRNA expression levels of these cytokines. Cell apoptosis was observed by TUNEL staining and the levels of Bcl-2, Bax, cleaved caspase 3 and cleaved caspase 9 were assayed by western blotting. Western blotting was also performed to detect the expression levels of endoplasmic reticulum (ER) stress-related proteins activating transcription factor 6, CCAAT-enhancer-binding protein homologous protein, inositol-requiring enzyme 1 and cleaved caspase 12 in bEECs. LPS treatment reduced cell viability and HKL treatment improved the viability of bEECs after LPS treatment. The LPS-induced inflammatory response and apoptosis in bEECs were also inhibited by HKL treatment. Additionally, the increased expression of ER stress-related proteins induced by LPS was reversed by HKL treatment. Following stimulation with the ER stress inducer tunicamycin, it was revealed that HKL attenuated ER stress and inhibited LPS-induced inflammatory response and apoptosis in bEECs. In summary, HKL inhibited ER stress associated with LPS-induced inflammation and apoptosis in bEECs, providing evidence that HKL can serve to be a novel agent for the treatment of endometritis.

The Diagnostic Criteria for Chronic Endometritis: A Survey of Pathologists

While acute endometritis is a reasonably well-defined entity of ascending infection and attendant active inflammation, chronic endometritis is less well defined. As part of a broad effort to define and refine the diagnostic criteria and management of the disease, we conducted a survey of pathologists to understand the variability in diagnostic criteria and implications of the diagnosis of nonspecific, nonobstetric chronic endometritis. Members of national and international professional pathology societies were surveyed utilizing anonymous electronic surveys designed to examine diagnostic criteria, etiological understanding and treatment implications of a pathologic diagnosis of nonspecific, nonobstetric chronic endometritis. There was substantial variability among pathologists in the diagnostic criteria used for making a diagnosis of nonspecific, nonobstetric chronic endometritis, with 28.5% of pathologists using the presence of a single plasma cell for making the diagnosis. There was additional variability in the use of special stains, reporting in the presence of coexisting lesions and the hormonal stage of the endometrium. There were no differences between generalists and specialists in the diagnostic criteria used, except the significantly greater likelihood of specialists making the diagnosis in gestational endometrium. The substantial variability in diagnostic criteria for nonspecific, nonobstetric chronic endometritis among pathologists, including among gynecologic pathologists, has the potential to confound the management of patients. Standardization of diagnostic criteria for chronic endometritis is essential to understand the implications of the diagnosis.

Relation between chronic endometritis and recurrent miscarriage

Introduction

Growing interest has focused on the relation between chronic endometritis (CE) or asymptomatic inflammation of the endometrium and recurrent miscarriage (RM).The aim of the study was to assess the relation between CE and RM and the accuracy of hysteroscopy in diagnosing CE.

Material and methods

One hundred and ten (110) women with unexplained RM were included in this study. Participants were subjected to diagnostic hysteroscopy for uterine cavity, and endometrium evaluation. The diagnosis of CE during hysteroscopic examination was based on CE-related hysteroscopic signs (micro-polyps, stromal edema, and/or hyperemia). At the end of hysteroscopy, an endometrial biopsy was taken from participants for culture, and immunohistochemical (IHC) staining. Collected data were analyzed to assess the relation between CE and RM and the accuracy of hysteroscopy in diagnosing CE.

Results

The prevalence of CE in women with RM was 31.8% using CE-related hysteroscopic signs, while it was 38.2% using IHC staining and endometrial cultures (p = 0.4). CE-related hysteroscopic signs had 64.1% sensitivity, 85.9% specificity, 71.4% positive predictive value (PPV), 81.3% negative predictive value (NPV), and 78.2% overall accuracy in diagnosing CE. Most cases of CE (> 81%) were caused by Mycoplasma and common pathogens.

Conclusions

The prevalence of CE in women with RM was 31.8% using CE-related hysteroscopic signs, while it was 38.2% using IHC staining and endometrial cultures. CE-related hysteroscopic signs had 64.1% sensitivity, 85.9% specificity, 71.4% PPV, 81.3% NPV, and 78.2% overall accuracy in diagnosing CE. Most cases of CE (> 81%) were caused by Mycoplasma and common pathogens.

Management of recurrent miscarriages: an overview of current evidence

PURPOSE OF REVIEW

Recurrent miscarriage (RM) or recurrent pregnancy loss (RPL) is defined as the consecutive loss of two or more pregnancies before the age of viability. The exact prevalence of RM is unknown, but it has been reported between 1% and 2%. The objective of this review is to provide a critical summary of the latest evidence for the investigation and management of women with RM.

RECENT FINDINGS

RMs are associated with multiple factors including increased female age and lifestyle habits, as well as genetic factors, hereditary and acquired thrombophilia and infections. Metabolic and endocrine factors, in addition to anatomical causes such as uterine malformations have also been suggested as a causative factors of RM.

SUMMARY

The management of RM would be expected to cause specific, however, in the majority of the cases no cause is identified, and the factors associated with RM may not be causally related with the condition.

Endometrial polyps with increased plasma cells are associated with chronic endometritis in infertility patients: Hysteroscopic findings and post-polypectomy pregnancy rates

PURPOSE

The relationship between endometrial polyps (EPs), chronic endometritis (CE), hysteroscopic findings, and antimicrobial in infertility patients was determined.

METHODS

We retrospectively enrolled 115 infertility patients with suspected EPs who underwent office hysteroscopy. Patients were divided into 3 groups: 38 with increased plasma cells in EPs (group 1); 31 without increased plasma cells in EPs (group 2); and 46 without EPs (group 3). The 3 groups underwent hysteroscopy with or without polypectomies, and immediately thereafter, an endometrial aspiration biopsy (EAB) was performed. CE was diagnosed based on plasma cell infiltration in the non-polypoid endometrium obtained by EAB.

RESULTS

The percentage of CE was 68.4%, 32.2%, and 28.3% in groups 1, 2, and 3, respectively. CE was more frequent in group 1 than group 2 or 3 (P = .01 and P = .002, respectively). The number of polyps was higher in group 1 than group 2. After adjustment for age and assisted reproductive technology, antibiotic therapy was not associated with pregnancy (adjusted odds ratio, 0.44; 95% confidence interval, 0.05-3.57) in patients with EPs and CE.

CONCLUSIONS

Group 1 was associated with CE, and hysteroscopic findings were different from group 2. Antibiotic therapy after polypectomy for EPs with CE may not always be necessary.

Novel approaches to the management of recurrent pregnancy loss: The OPTIMUM (OPtimization of Thyroid function, Thrombophilia, Immunity, and Uterine Milieu) treatment strategy

PURPOSE

Does the OPtimization of Thyroid function, Thrombophilia, Immunity, and Uterine Milieu (OPTIMUM) treatment strategy, developed for treating repeated implantation failure (RIF), contribute to improving pregnancy outcomes in patients with a history of recurrent pregnancy loss (RPL)?

METHODS

Between 2018 and 2019, women with RPL after two or more clinical pregnancy losses underwent RPL testing. We treated chronic endometritis with antibiotics, high Th1/Th2 cell ratios with vitamin D and/or tacrolimus, overt/subclinical hypothyroidism with levothyroxine, and thrombophilia with low-dose aspirin. Of 168 consecutive women aged ≤43 years, 115 underwent RPL testing. We compared 100 pregnancies (90 women) and 46 pregnancies (41 women) with and without the OPTIMUM treatment strategy, respectively.

RESULTS

RPL testing identified intrauterine abnormalities in 66 (57.4%), elevated Th1/Th2 cell ratios in 50 (43.5%), thyroid dysfunction in 33 (28.7%), and thrombophilia in 33 (28.7%). The live birth rate in the OPTIMUM group was significantly higher than that in the control group among women aged <40 years (78.1% and 42.3%, respectively; p = 0.002), but no significant difference was observed in women aged ≥40 years (55.6% and 30.0%, respectively; p = 0.09).

CONCLUSIONS

The OPTIMUM treatment strategy improved pregnancy outcomes in patients with not only RIF but also RPL.

THE CAPACITY OF PHYSICAL THERAPY FOR REPEATED IMPLANTATION FAILURES IN IVF PROGRAMS: A LITERATURE REVIEW

Relevance: Studies of the etiology and pathogenesis of implantation failures, both repeated and primary, as well as the possibilities of therapy today carry many contraversions. However, in recent years, numerous studies have demonstrated the high effectiveness of various physiotherapy methods in improving reproductive outcomes, including therapy and overcoming repeated implantation failures in in-vitro fertilization programs. The purpose of the study was to study the capacity of physical therapy for repeated implantation failures in in-vitro fertilization programs. Materials and Methods: The capacity of physical therapy for repeated implantation failures in in-vitro fertilization programs were studied through the search and analysis of the scientific sources for 1995-2021, available in the Scopus and Pubmed databases, using the keywords “in-vitro fertilization,” “repeated implantation failure,” “assisted reproductive technology,” and «physiotherapy.» Results: Electrical impulse therapy has established itself as the most studied method in the treatment of disorders of endometrial receptivity with proven efficacy. Physical methods of exposure can improve reproductive outcomes through a beneficial effect on the angiogenesis and architectonics of the endometrium, improving its receptivity, and normalizing physiology. Further detailed study of the etiology, pathogenetic mechanisms, as well as the effectiveness of overcoming repeated implantation failures by various methods is needed to develop treatment protocols.

Evaluation of artificial intelligence using time-lapse images of IVF embryos to predict live birth

RESEARCH QUESTION

Can artificial intelligence (AI) improve the prediction of live births based on embryo images?

DESIGN

The AI system was created by using the Attention Branch Network associated with deep learning to predict the probability of live birth from 141,444 images recorded by time-lapse imaging of 470 transferred embryos, of which 91 resulted in live birth and 379 resulted in non-live birth that included implantation failure, biochemical pregnancy and clinical miscarriage. The possibility that the calculated confidence scores of each embryo and the focused areas visualized in each embryo image can help predict subsequent live birth was examined.

RESULTS

The AI system for the first time successfully visualized embryo features in focused areas that had potential to distinguish between live and non-live births. No visual feature of embryos were visualized that were associated with live or non-live births, although there were many images in which high-focused areas existed around the zona pellucida. When a cut-off level for the confidence score was set at 0.341, the live birth rate was significantly greater for embryos with a score higher than the cut-off level than for those with a score lower than the cut-off level (P < 0.001). In addition, the live birth rate of embryos with good morphological quality and confidence scores higher than 0.341 was 41.1%.

CONCLUSIONS

The authors have created an AI system with a confidence score that is useful for non-invasive selection of embryos that could result in live birth. Further study is necessary to improve selection accuracy.

Identification of Uterine Microbiota in Infertile Women Receiving in vitro Fertilization With and Without Chronic Endometritis

In vitro fertilization (IVF) is an important assisted reproductive technology in treating infertility, whose failure rate is still high. Studies suggested that uterine microbiota are related to women’s reproductive diseases and persisting intrauterine bacterial infectious conditions, such as chronic endometritis (CE), impairing the pregnant processes. However, the relationship between uterine microbiota and IVF outcomes is still an open question. In the present study, 94 patients diagnosed with infertility were enrolled and were divided into CE (E group, n = 25) and non-CE (NE group, n = 69) groups depending on the hysteroscopy and immunohistochemistry. Subsequently, E (Ep, n = 8 and Enp, n = 17) and NE (NEp, n = 41 and NEnp, n = 28) groups were divided into pregnancy and non-pregnancy groups depending on the IVF outcomes, respectively. The uterine fluids were collected and microbial profiles were examined through the V4 region of 16S rRNA gene high-throughput sequencing. The results demonstrated that patients with CE had significantly lower clinical pregnancy rate compared with the non-CE patients (32 vs. 58.42%, p = 0.0014). The relative abundances of Proteobacteria and Acidobacteria were higher in the non-CE group, whereas high abundances of Actinobacteria and Fusobacteria were observed in the CE group at the phylum level. At the genus level, high relative abundances of Gardnerella were observed in the CE group and non-pregnancy groups, which significantly referred to the negative IVF outcome. In conclusion, CE may be a key factor for the negative outcome after IVF, of which the uterine microbiota plays a pivotal role, and the microbial diversity in uterine may serve as a biomarker to forecast the success of IVF outcome.

Correlation between hysteroscopy findings in patients with hydrosalpinx and chronic endometritis

OBJECTIVE

To evaluate the role of hydrosalpinx in susceptibility to chronic endometritis (CE).

METHODS

This is a retrospective cohort study, which includes 624 patients with hydrosalpinx (group A) and 789 patients without hydrosalpinx (group B) undergoing laparoscopy and hysteroscopy simultaneously. Endometrial morphology was recorded under hysteroscopy. Endometrial biopsy was obtained after hysteroscopy, and immunohistochemical staining for syndecan-1 (CD138) was carried out.

RESULTS

No significantly statistical differences were found between the two groups when comparing the incidence of endometrial hyperemia or endometrial micro-polyps under hysteroscopy (P > 0.05). Hydrosalpinx had a significant impact on the incidence of CE (P < 0.05) (plasma cell count: no plasma cells: odds ratio [OR] 0.71, 95% confidence interval [CI] 0.58-0.88, P = 0.002; ≥1/high-power field [HPF]: OR 1.40, 95% CI 1.14-1.74, P = 0.002; ≥3/HPF: OR 1.50, 95% CI 1.18-1.91, P = 0.001; ≥5/HPF: OR 1.62, 95% CI 1.27-2.21, P < 0.001). There were no significant differences in the comparison of plasma cell count between the unilateral hydrosalpinx group (274 patients) and the bilateral hydrosalpinx group (350 patients) (P > 0.05).

CONCLUSION

The presence of hydrosalpinx increased the incidence of CE. Bilateral hydrosalpinx did not significantly increase the incidence of CE compared with unilateral hydrosalpinx.

Pharmacological activation of rev-erbα suppresses LPS-induced macrophage M1 polarization and prevents pregnancy loss

BACKGROUND

Circadian rhythm is an important player for reproduction. Rev-erbα, a significant clock gene, is involved in regulating cell differentiation, inflammation and metabolism. Macrophage polarization plays crucial roles in immune tolerance at the maternal-fetus interface, which also modulates the initiation and resolution of inflammation. Alteration of macrophage polarization induces adverse pregnancy outcomes such as infertility, recurrent spontaneous abortion and preterm labor.

RESULTS

Decidual macrophages from LPS-induced mice abortion model displayed M1-like bias, accompanied by decreased expression of Rev-erbα. SR9009, an agonist of Rev-erbα, may reduce lipopolysaccharide (LPS)-induced M1 polarization of macrophages via activation of PI3K but not NF-κB signaling pathway. Furthermore, SR9009 could reduce M1-like polarization of decidual macrophages induced by LPS and attenuate LPS-induced resorption rates in mice model.

CONCLUSIONS

Both in vivo and in vitro experiments demonstrated that the pharmacological activation of Rev-erbα using SR9009 could attenuate the effect of LPS on macrophage polarization and protect pregnancy. This study may provide a potential therapeutic strategy for miscarriage induced by inflammation.

Treatment following hysteroscopy and endometrial diagnostic biopsy increases the chance for live birth in women with chronic endometritis

Problem

Repeated implantation failure and recurrent pregnancy loss are associated with chronic endometritis, a persistent endometrial inflammation. Its diagnosis and treatment may increase pregnancy and live birth rates. The aim of this study was to assess the effectiveness of endometrial diagnostic biopsy and subsequent antibiotic treatment in cases of chronic endometritis on reproductive outcomes over a long observation period.

Method of Study

We conducted a historical cohort study (2014–2018) at our University‐based infertility center that included women (n = 108) with repeated implantation failure or recurrent pregnancy loss without known pathologies associated with either condition. Forty‐one women underwent a hysteroscopy only (reference group); the remaining 67 women underwent, in addition to the hysteroscopy, an endometrial diagnostic biopsy with immunohistochemically staining for CD138 to detect plasma cells (biopsy group). If one or more plasma cells were detected, the women were treated with doxycycline 100 mg twice a day orally for 2 weeks. We performed stratified survival analysis (Kaplan‐Meier) and Cox regression.

Results

The biopsy group had higher chances of pregnancy (hazard ratio 2.28; 95% confidence interval 1.23–4.24; p = .009) and of live birth (hazard ratio 2.76; 95% confidence interval 1.30–5.87; p = .008) compared with the reference group. In the sensitivity analysis, repeated implantation failure or recurrent pregnancy loss did not affect the outcome.

Conclusion

Endometrial diagnostic biopsy followed by antibiotic treatment in case of chronic endometritis in women with repeated implantation failure or recurrent pregnancy loss may increase the chances for live birth.

Clinical consequences of defective decidualization

Decidualization is characterized by a series of genetic, metabolic, morphological, biochemical, vascular and immune changes occurring in the endometrial stroma in response to the implanting embryo or even before conception and involves the stromal cells of the endometrium. It is a fundamental reproductive event occurring in mammalian species with hemochorial placentation. A growing body of experimental and clinical evidence strongly suggests that defective or disrupted decidualization contributes to the establishment of an inappropriate maternal-fetal interface. This has relevant clinical consequences, ranging from recurrent implantation failure and recurrent pregnancy loss in early pregnancy to several significant complications of advanced gestation. Moreover, recent evidence indicates that selected diseases of the endometrium, such as chronic endometritis and endometriosis, can have a detrimental impact on the decidualization response in the endometrium and may help explain some aspects of the reduced reproductive outcome associated with these conditions. Further research efforts are needed to fully understand the biomolecular mechanisms ans events underlying an abnormal decidualization response. This will permit the development of new diagnostic and therapeutic strategies aimed to improve the likelihood of achieveing a successful pregnancy.

Immunological Testing in Assisted Reproductive Technology

Fetal implantation requires carefully orchestrated involvement of the maternal immune system. Aberrant function within implantation has been suggested as a cause of implantation failure. The emergence of immunological theories of miscarriage has led to immunological testing as an adjuvant treatment in assisted reproductive technology; however, it remains controversial, with mixed evidence both for immunological cause and the benefits of immunological testing. Literature on common methods of immunological testing within assisted reproductive technology is reviewed including those of peripheral and uterine natural killer cells, chronic endometritis, and T-helper cells cytokine ratio. There is little consensus in the evidence on immunological testing in the context of recurrent implantation failure. The field is limited by a lack of uniformity in approach to testing and heterogeneity of the pathophysiological cause. Nevertheless, the maternal immune system is heavily involved in implantation and the new era of personalized medicine ensures that a more defined approach to immunological testing will be achieved.

Hysteroscopic detection of chronic endometritis: Evaluating proposed hysteroscopic features suggestive of chronic endometritis

PURPOSE

To evaluate the proposed criteria in a large sample and in additional subgroups in order to test the validity of the hysteroscopic features widely-accepted as suggestive of CE.

METHOD(S)

All patients (n: 2675) underwent outpatient hysteroscopy, with the vaginoscopic approach technique. Hysteroscopic features such as, stromal oedema, diffuse or focal hyperaemia, "strawberry aspect", micropolyposis and endometrial polyps, are often indicate the presence of chronic endometritis. All hysteroscopic features, alone and in combination were applied in 7 (seven) different subgroups of the sample: total sample, women in reproductive age, women with infertility issues/IVF screening, women with history of recurrent miscarriages, menopausal women, and women with hysteroscopic indication of Abnormal Uterine Bleeding (AUB) in women of reproductive age and postmenopausal bleeding (PMB). From each case, endometrial samples were obtained and immunohistochemistry, identifying CD-138, was applied in order to diagnose CE.

RESULT(S)

A total of 2675 patients were included of which, 1444 women were found with at least one of the proposed hysteroscopic features mentioned above. Stromal oedema, focal or diffuse hyperaemia and "strawberry aspect" in combination with micropolyposis demonstrated higher rates of diagnostic accuracy in the detection of CE correlated to histologic confirmation. Micropolyposis, stromal oedema, focal or diffuse hyperaemia and "strawberry aspect" offer great diagnostic accuracy in the hysteroscopic detection of Chronic Endometritis, regardless reproductive status and/or clinical presentation. Endometrial polyps are not valid hysteroscopic features in cases of suspected CE.

CONCLUSION(S)

Diagnostic hysteroscopy can accurately diagnose cases of CE, based on stromal oedema, focal or diffuse hyperaemia and "strawberry aspect", in combination with micropolyposis. In subgroups of infertile women, higher diagnostic accuracy based on the hysteroscopic features mentioned, was more likely to be achieved. Whether endometrial polyps are suggestive of CE, when identified during office hysteroscopy, remains controversial.

MicroRNA: Could It Play a Role in Bovine Endometritis?

Endometritis in dairy cows is a major economic problem worldwide; without advances in lifestyle management and drug treatment, it causes high morbidity and death. Micro ribonucleic acid (miRNAs) these days is seen as an important part of gene control networks. It is a class of small nucleotides 20-25, single-stranded RNA molecules. In endometritis, the inflammatory response caused by the gram-negative bacteria Escherichia coli (E. coli) alters the expression of miRNA which can regulate the innate immune system. This manuscript reviews (1) the interaction of miRNAs with the signaling of NF-κB and dysregulation of miRNAs and NF-κB activity in endometritis and (2) the activity of miR-let-7c, miR-148a, and miR-488 in NF-κB activation and their effect on endometritis. Cows with reduced immunity are more vulnerable to transition diseases, such as endometritis. During post-partum, cows undergo stress, metabolic disorders, hormonal imbalance, negative energy balance, and changes in diet. One of the many categories of regulatory molecules, which explain its natural function and pathological impact on NF-κB dysregulation, is important to inform the complexity of the immune system and to develop treatments for endometritis. It shows that miRNAs could have multiple applications in veterinary medicine. Nevertheless, a comprehensive study of is essential which should be aimed at exploring the role of microRNA at physiological level and its effect due to dysfunction and dysregulation.

Combination of Dydrogesterone and Antibiotic Versus Antibiotic Alone for Chronic Endometritis: a Randomized Controlled Trial Study

To evaluate the impact of dydrogesterone in the treatment of chronic endometritis with antibiotic treatment in premenopausal women. A total of 188 chronic endometritis patients diagnosed by syndecan-1 (CD138) expression were enrolled in this randomized controlled trial study. Dydrogesterone and doxycycline were given in the treatment group, while single antibiotic was given in the control group. CD138, estrogen receptor, and progesterone receptor expression in samples of the endometrium was analyzed by immunohistochemistry. Comparison of chronic endometritis cure rate between groups was performed based on conversion of CD138 expression from positive to negative. The 188 cases included in the statistical analysis consisted of 93 cases in the treatment group and 95 cases in the control group. The cure rates of chronic endometritis in the dydrogesterone and antibiotic combination group and the single antibiotic group were 86.0% (80/93) and 72.6% (69/95), respectively, with an overall cure rate of 79.3% (149/188). The dydrogesterone and antibiotic combination group showed better effects regarding the cure rate of chronic endometritis (P<.05). Multivariate analysis showed that the cure rate of chronic endometritis was not affected by age, clinical diagnosis, hysteroscopic resection, estrogen receptor status, or progesterone receptor status (all P>.05). Addition of dydrogesterone was effective for the treatment of chronic endometritis with antibiotic treatment in premenopausal women. The study was retrospectively registered to Chinese Clinical Trial Registry (ChiCTR2000040227) in November 2020.

Induction of the epithelial-mesenchymal transition in the endometrium by chronic endometritis in infertile patients

Background

The purpose of the present study was to evaluate the relationship between chronic endometritis and the epithelial-mesenchymal transition in the endometrium of infertile patients in the implantation phase.

Methods

Endometrial biopsy specimens from 66 infertility patients were analyzed. The presence of chronic endometritis was investigated by immunostaining for CD138. Immunohistochemical staining for E-cadherin, N-cadherin, Slug, and Snail was performed, and the expression profiles were statistically analyzed according to the presence of chronic endometritis. When the loss of E-cadherin expression and/or the positive expression of N-cadherin was detected, the specimen was considered epithelial-mesenchymal transition-positive. Epithelial-mesenchymal transition-positive cases were also statistically analyzed according to the presence of chronic endometritis. The characteristics of the patients in the epithelial-mesenchymal transition-positive and epithelial-mesenchymal transition-negative groups were compared. The association between variables, including age, body mass index, gravidity, parity, and each causative factor of infertility and epithelial-mesenchymal transition positivity was analyzed.

Results

The rates of the loss of E-cadherin expression, the gain of N-cadherin and epithelial-mesenchymal transition positivity were significantly higher in chronic endometritis patients. The expression of Slug, cytoplasmic Snail, and nuclear Snail was also detected at significantly higher rates in chronic endometritis patients. Chronic endometritis were related to the epithelial-mesenchymal transition.

Conclusion

The epithelial-mesenchymal transition was frequently detected in the endometrium in infertile patients with chronic endometritis. Since the epithelial-mesenchymal transition is associated with chronic endometritis, the epithelial-mesenchymal transition appears to be involved in the alteration of mechanisms of implantation.

Histological diagnostic criterion for chronic endometritis based on the clinical outcome

BACKGROUND

The diagnostic criteria of chronic endometritis remain controversial in the treatment for infertile patients.

METHODS

A prospective observational study was conducted in a single university from June 2014 to September 2017. Patients who underwent single frozen-thawed blastocyst transfer with a hormone replacement cycle after histological examination for the presence of chronic endometritis were enrolled. Four criteria were used to define chronic endometritis according to the number of plasma cells in the same group of patients: 1 or more (≥ 1) plasma cells, 2 or more (≥ 2), 3 or more (≥ 3), or 5 or more (≥ 5) in 10 high-power fields. Pregnancy rates, live birth rates, and miscarriage rates of the non-chronic endometritis and the chronic endometritis groups defined with each criterion were calculated. A logistic regression analysis was performed for live births using eight explanatory variables (seven infertility factors and chronic endometritis). A receiver operating characteristic curve was drawn and the optimal cut-off value was calculated.

RESULTS

A total of 69 patients were registered and 53 patients were finally analyzed after exclusion. When the diagnostic criterion was designated as the presence of ≥ 1 plasma cell in the endometrial stroma per 10 high-power fields, the pregnancy rate, live birth rate, and miscarriage rate were 63.0% vs. 30.8%, 51.9% vs. 7.7%, and 17.7% vs. 75% in the non-chronic and chronic endometritis groups, respectively. This criterion resulted in the highest pregnancy and live birth rates among the non-chronic endometritis and the smallest P values for the pregnancy rates, live birth rates, and miscarriage rates between the non-chronic and chronic endometritis groups. In the logistic regression analysis, chronic endometritis was an explanatory variable negatively affecting the objective variable of live birth only when chronic endometritis was diagnosed with ≥ 1 or ≥ 2 plasma cells per 10 high-power fields. The optimal cut-off value was obtained when one or more plasma cells were found in 10 high-power fields (sensitivity 87.5%, specificity 64.9%).

CONCLUSIONS

Chronic endometritis should be diagnosed as the presence of ≥ 1 plasma cells in 10 high-power fields. According to this diagnostic criterion, chronic endometritis adversely affected the pregnancy rate and the live birth rate.

Gut microbiota mediate the protective effects on endometritis induced by Staphylococcus aureus in mice

Endometritis, the inflammation of the endometrial lining caused by bacterial pathogens, is associated with reproductive failure. Recent studies have shown that gut microbiota play an important role in infectious diseases. However, the roles of the gut microbiota in endometritis remain unclear. Here, we assessed the effects and mechanisms of the gut microbiota during endometritis induced by Staphylococcus aureus (S. aureus). A mouse gut microbiota-dysbiosis model was established by a mixture of antibiotics (Abx) and subsequently, a model of endometritis was established by the uterine perfusion of S. aureus. Fecal microbiota transplantation (FMT) was performed to evaluate the relationship between gut microbiota and endometritis. The results showed that the mice with gut microbiota-dysbiosis developed uterine inflammation, while this inflammatory response of the uterus was alleviated in mice with FMT to gut microbiota-dysbiosis. In addition, S. aureus-induced endometritis was greater in severity in the mice with gut dysbiosis as compared to the untreated mice. Moreover, these effects were reversed in mice with FMT to the gut microbiota-dysbiosis. GC-MS analysis demonstrated that the levels of short-chain fatty acids (SCFAs) in the feces of mice with gut microbiota-dysbiosis significantly decreased and pretreatment with sodium butyrate or sodium propionate increased the concentrations of butyrate or propionate in both the circulation and uterine tissues, thereby reducing the severity of endometritis induced by S. aureus. In addition, the increased pathogen load in the uteri of the mice with gut microbiota-dysbiosis was associated with a reduction in the phagocytic ability and responsiveness of neutrophils. In conclusion, the gut microbiota offer a protective effect against S. aureus-induced endometritis by regulating the levels of SCFAs and maintaining the phagocytic ability and responsiveness of neutrophils.

Endometrial causes of recurrent pregnancy losses: endometriosis, adenomyosis, and chronic endometritis

Chronic inflammatory processes affecting the endometrium, as encountered in endometriosis, adenomyosis, and chronic endometritis, alter endometrial receptivity. These disorders are associated with early pregnancy losses and possibly recurrent pregnancy losses (RPL). In the cases of endometriosis, other factors associated with the disease also are susceptible of causing miscarriages and possibly RPL, such as an impact of intrapelvic inflammatory processes affecting the oocyte and embryo in case of natural conception. Conversely these latter effects obviously are bypassed in case of assisted reproductive technology. Chronic inflammation of the endometrium in the condition known as chronic endometritis also causes early pregnancy losses and RPL with beneficial effects achieved when specific treatment is undertaken.

Efficacy of therapies and interventions for repeated embryo implantation failure: a systematic review and meta-analysis

The aim of the present systematic review and meta-analysis was to assess the effect of the different therapeutic options for repeated embryo implantation failure (RIF) on a subsequent IVF cycle outcome. Twenty-two RCTs and nineteen observational studies were included. Pooling of results showed a beneficial effect of intrauterine PBMC infusion on both CPR (RR 2.18; 95% CI 1.58-3.00; p < 0.00001; OR 2.03; 95% CI 1.22-3.36; p = 0.006) and LBR (RR 2.41; 95% CI 1.40-4.16; p = 0.002; OR 3.73; 95% CI 1.13-12.29; p = 0.03), of subcutaneous G-CSF administration on CPR (RR 2.29; 95% CI 1.58-3.31; p < 0.0001) and of intrauterine PRP infusion on CPR (RR 2.45; 95% CI 1.55-3.86; p = 0.0001). Observational studies also demonstrated a positive effect of IVIG and intrauterine hCG infusion on both CPR and LBR and of atosiban on CPR. Studies investigating intrauterine G-CSF infusion, LMWH, intravenous intralipid, hysteroscopy, blastocyst-stage ET, ZIFT, PGT-A and AH failed to observe an impact on IVF outcome. The quality of the evidence that emerged from RCTs focused on intrauterine PBMC infusion and subcutaneous G-CSF administration was moderate. For all other therapies/interventions it varied from low to very low. In conclusion, intrauterine PBMC infusion and subcutaneous G-CSF administration are the most promising therapeutic options for RIF. However, further well conducted RCTs are necessary before their introduction into clinical practice.

Endometrial Status in Queens Evaluated by Histopathology Findings and Two Cytological Techniques: Low-Volume Uterine Lavage and Uterine Swabbing

Simple Summary

The endometrium health of feline queens can be difficult to assess due to the reduced size of the uterus, which hinders representative biopsy sampling. This may result in limitations in diagnosing endometritis, and consequently in detecting infertility problems. Although histology is considered the most reliable technique for diagnosing endometritis in many species, cytology is also gaining importance and may be an alternative tool for evaluating the endometrium in small species. Two different common cytological techniques (uterine lavage and uterine swabbing) were compared to determine the reliability of cytology for evaluating the endometrium status in queens. Histopathological and bacteriological information was used for the control methods. Our results demonstrated that cytology may be a useful diagnostic tool for assessing the endometrial status. In addition, when comparing cytological techniques, the uterine lavage method was more representative than uterine swabbing.

Abstract

Endometritis is associated with fertility problems in many species, with endometrial biopsy being the main diagnostic tool. In feline queens, the reduced size of the uterus may make it difficult to obtain representative diagnostic samples. Endometrial cytology may represent a valuable diagnostic tool for evaluating the health status of the endometrium in queens. Fifty domestic shorthair queens were included and divided into two cytological diagnostic technique groups, the uterine lavage (UL; n = 28) and uterine swabbing (US; n = 22) groups. Cytological results were compared with histopathological and bacteriological information. Changes in the histopathological patterns were also evaluated and compared with progesterone levels to confirm previous published data. Furthermore, the results from both cytological sampling methods were compared to evaluate the utility of each method. Endometritis was ruled out in all queens by means of histology and microbiology. Leukocyte counts and red blood cell/endometrial cell ratios were significantly higher in US than UL samples. Additionally, UL sampling is less affected by blood contamination and cells are better preserved. The combination of endometrial cytology and uterine culture might be useful for evaluating the endometrial characteristics in queens. The UL evaluation method is more representative of the actual endometrial status than the US technique.

Hysteroscopy and female infertility: a fresh look to a busy corner

Hysteroscopy has evolved from the traditional art of examining the uterine cavity for diagnostic purposes to an invaluable modality to concomitantly diagnose and (see and) treat a multitude of intrauterine pathologies, especially in the field and clinics specialising in female reproduction. This article reviews the literature on the most common cervical, endometrial, uterine and tubal pathologies such as chronic endometritis, endometrial polyps, adenomyosis, endometriosis, endometrial atrophy, adhesions, endometrial hyperplasia, cancer, and uterine malformations. The aim is to determine the efficiency of hysteroscopy compared with other available techniques as a diagnostic and treatment tool and its association with the success of in vitro fertilisation procedures. Although hysteroscopy requires an experienced operator for optimal results and is still an invasive procedure, it has the unique advantage of combining great diagnostic and treatment opportunities before and after ART procedures. In conclusion, hysteroscopy should be recommended as a first-line procedure in all cases with female infertility, and a special effort should be made for its implementation in the development of new high-tech procedures for identification and treatment infertility-associated conditions.

Alteration in endometrial helper T-cell subgroups in chronic endometritis

PROBLEM

The effect of chronic endometritis (CE) on the subpopulation of CD4⁺ T cells, Th1, Th2, Th17, and regulatory T cells in the endometrium is unknown.

METHOD OF STUDY

Lymphocytes were isolated from the endometrium of CE patients (n = 12) and non-CE patients (n = 7). The CD4⁺ T-cell profile was analyzed by flow cytometry and immunofluorescence.

RESULTS

In the endometrium of CE patients, there were significantly more Th1 cells among CD4⁺ cells and fewer Th2 cells in comparison to non-CE patients. No marked difference was observed in Th17 cells or Foxp3⁺ Treg cells. Moreover, the proportion of Th1 cells increased and the proportion of Th2 cells decreased as the number of CD138⁺ cells increased. Furthermore, when the localization of CD138⁺ cells and CD4⁺ cells was examined, CD4⁺ cells were found to be clustered around CD138⁺ cells in CE patients.

CONCLUSION

The CD4⁺ T-cell profile in the endometrium is altered in women with CE. This finding may help to clarify the pathophysiology and development of treatment methods for CE.

Application of Hydrogel-Based Delivery System in Endometrial Repair

A receptive endometrium with proper thickness is essential for successful embryo implantation. However, endometrial injury caused by intrauterine procedures often leads to pathophysiological changes in its environment, resulting in subsequent female infertility. Among diverse treatment methods of endometrial injury, hydrogels are a class of hydrophilic three-dimensional polymeric network with biocompatibility as well as the capability of absorbing water and encapsulation, which have potential applications as a promising intrauterine controlled-release delivery system. This review summarizes recent advances in the approaches of endometrial repair and further focuses on the application of a hydrogel-based delivery system in endometrial repair, including its preparation, therapeutic loading considerations, clinical applications, as well as working mechanisms.

The effects of chronic endometritis on the pregnancy outcomes

PROBLEM

Chronic endometritis (CE) influences the clinical outcomes of assisted reproductive technology. However, the effect of CE on the pregnancy outcome is still unknown.

METHOD OF STUDY

A retrospective case-control study was conducted in a single university. Subjects who conceived by in vitro fertilization within a year after a histological diagnosis of CE under 40 years of age from September 2013 to December 2017 were extracted. The rates of miscarriage, preterm birth, term birth, and live birth per pregnancy according to the presence or absence of CE were analyzed. A logistic regression analysis was performed for miscarriage, preterm birth, term birth, and live birth for eight explanatory variables of seven infertility factors and CE.

RESULTS

A total of 39 pregnancies in 38 subjects with non-CE and 35 pregnancies in 32 subjects with CE were ultimately analyzed. The rates of miscarriage, preterm birth, term birth, and live birth per pregnancy were 12.8% and 40.0% (P < .03), 2.6% and 14.3% (P = .1), 84.6% and 45.7% (P < .001) and 84.6% and 57.1% (P < .03) in the Non-CE and CE groups, respectively, although only the analysis for tem birth rate had sufficient power to exclude Type II error. In logistic analysis, CE was a factor affecting the objective variables of miscarriage, term birth, and live birth.

CONCLUSIONS

The term birth rate among pregnancies decreased mainly due to an increase in miscarriages when CE was detected before pregnancy in patients treated with in vitro fertilization. A histopathological diagnosis of CE adversely affected the term birth rate per pregnancy.

Brucella abortus and Pregnancy in Mice: Impact of Chronic Infection on Fertility and the Role of Regulatory T Cells in Tissue Colonization

Stealthy intracellular bacterial pathogens are known to establish persistent and sometimes lifelong infections. Some of these pathogens also have a tropism for the reproductive system, thereby increasing the risk of reproductive disease and infertility. To date, the pathogenic mechanism involved remains poorly understood. Here, we demonstrate that Brucella abortus, a notorious reproductive pathogen, has the ability to infect the nonpregnant uterus, sustain infection, and induce inflammatory changes during both acute and chronic stages of infection. In addition, we demonstrated that chronically infected mice had a significantly reduced number of pregnancies compared to naive controls. To investigate the immunologic mechanism responsible for uterine tropism, we explored the role of regulatory T cells (Tregs) in the pathogenesis of Brucella abortus infection. We show that highly suppressive CD4+FOXP3+TNFR2+ Tregs contribute to the persistence of Brucella abortus infection and that inactivation of Tregs with tumor necrosis factor receptor II (TNFR2) antagonistic antibody protected mice by significantly reducing bacterial burden both systemically and within reproductive tissues. These findings support a critical role of Tregs in the pathogenesis of persistence induced by intracellular bacterial pathogens, including B. abortus Results from this study indicate that adverse reproductive outcomes can occur as sequelae of chronic infection in nonpregnant animals and that fine-tuning Treg activity may provide novel immunotherapeutic and prevention strategies against intracellular bacterial infections such as brucellosis.

Menstrual Effluent Provides a Novel Diagnostic Window on the Pathogenesis of Endometriosis

Endometriosis is a chronic inflammatory disorder characterized by the presence of endometrial-like tissue growing outside of the uterus. Although the cause is unknown, retrograde menstruation leads to deposition of endometrial cells into the peritoneal cavity. Lack of disease recognition and long diagnostic delays (6–10 years) lead to substantial personal, social and financial burdens, as well as delayed treatment. A non-invasive diagnostic for endometriosis is a major unmet clinical need. Here, we assessed whether differences in menstrual effluent-derived stromal fibroblast cells (ME-SFCs) from women with and without endometriosis provide the basis for a non-invasive diagnostic for endometriosis. In addition, we investigated whether treatment of control ME-SFCs with inflammatory cytokines (TNF and IL-1β) could induce an endometriosis-like phenotype. ME-SFCs from laparoscopically diagnosed endometriosis patients exhibit reduced decidualization capacity, measured by IGFBP1 production after exposure to cAMP. A receiver operating characteristic (ROC) curve developed using decidualization data from controls and endometriosis subjects yielded an area under the curve of 0.92. In addition, a significant reduction in ALDH1A1 gene expression and increased podoplanin surface expression were also observed in endometriosis ME-SFCs when compared to control ME-SFCs. These endometriosis-like phenotypes can be reproduced in control ME-SFCs by exposure to inflammatory cytokines (TNF and IL-1β) and are associated with increased cell migration. These results are consistent with the hypothesis that chronic intrauterine inflammation influences the development of endometriosis lesions following retrograde menstruation. In conclusion, the analysis of ME-SFCs can provide an accurate, rapid, and non-invasive diagnostic for endometriosis and insight into disease pathogenesis.

Chronic endometritis and reproductive failure: Role of syndecan-1

Chronic endometritis (CE) is an unusual inflammatory condition characterized by endometrial plasmacyte infiltration. It has a high prevalence in women with reproductive failure. Because of its characteristic localization patterns and molecular functions, syndecan-1 has been identified as a biomarker of plasmacyte, and syndecan-1 immunohistochemistry (IHC) becomes the most dependable diagnostic method for CE. In this review, we discuss the association between CE and reproductive failure, the clinicopathological characterization of CE, the function and expression of syndecan-1, the progress of syndecan-1 IHC in the diagnosis of CE, and the prediction of reproductive outcome.

Relationship of chronic endometritis with chronic deciduitis in cases of miscarriage

BACKGROUND

The presence of chronic deciduitis (CD) was determined in patients diagnosed with or without chronic endometritis (CE) before pregnancy.

OBJECTIVE

To study the effect of CE on decidua in cases of miscarriage.

METHODS

Decidual tissue was obtained from the patients who miscarried at the first pregnancy within a year after the diagnosis of the presence or absence of CE. The number and distribution pattern of plasma cells stained with CD138 in decidual tissue in 10 high-power fields (HPFs) was examined. The prevalence of CD diagnosed with four different grade; grade 0, no plasma cell in 10 HPFs, thus Non-CD;grade 1, rare single plasma cells; grade 2, rare clusters or more than 5 single cells total; and grade 3, many plasma cells with more than 5 clusters, were examined and compared between Non-CE and CE.

RESULTS

The incidence rate of CD of grade2 + 3 was significantly higher in CE than Non-CE (53.8%; 7/13 vs. 0%; 0/13, P < 0.01). Presence of clusters or a number of plasma cells in 10 HPFs of decidua showed a sensitivity of 53.8%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 68.4% for the diagnosis of CE.

CONCLUSION

Presence of clusters of plasma cells or five or more of plasma cells in decidua was found in more than half of CE, but not found in Non-CE. When CD with cluster or five or more of plasma cells is confirmed histologically in miscarriage decidual tissue, the presence of CE before the pregnancy should be suspected.

Dienogest suppresses cellular proliferation status of endometrial polyps and acts differently depending on the morphological type

Administration of Dienogest prior to hysteroscopic polypectomy is empirically performed, but the physiological effects of Dienogest on endometrial polyps are unclear. We aimed to investigate the effects of Dienogest on the proliferation and inflammation of endometrial polyps. We conducted a retrospective case study on 40 menstruating women who underwent hysteroscopic polypectomy at our hospital. We collected clinical data, and the polyps were divided by morphological appearance. The specimens obtained were immunostained for Ki67 as a marker of cellar proliferation and CD138 as a marker of plasmacytes, which are a hallmark of chronic endometritis. Dienogest significantly suppressed the proliferation status of EPs because Dienogest treatment prior to the operation significantly reduced the Ki67 index (41.25 ± 16.85 vs 7.18 ± 9.82, p < 0.01). We found that sessile-type polyps showed a significantly lower Ki67 index than the pedunculated type (12.28 ± 11.12 vs 2.09 ± 2.73, p = 0.026). The presence of CD138-positive cells was more pronounced in sessile-type polyps than in pedunculated polyps (p = 0.018). However, Dienogest treatment showed no apparent effect on inflammation status, as detected by CD138-positive cells. We revealed that Dienogest suppressed cellular proliferation, and morphological classification of endometrial polyps could be used to predict the responsiveness to Dienogest. However, Dienogest might not affect cellular inflammation.