Intrafollicular inflammatory cytokines but not steroid hormone concentrations are increased in naturally matured follicles of women with proven endometriosis

Effect of interleukin 6 (IL-6) on sperm quality, kinematic parameters, acrosome integrity, apoptosis, ultrastructure, and molecular docking in cryopreserved ram spermatozoa

Sperm cryopreservation can lead to subfertility due to potential damage to sperm DNA, membranes, and overall motility caused by the freeze-thaw process. Interleukin-6 (IL-6) is a versatile cytokine with various roles in reproductive processes. However, the impacts of IL-6 supplementation on cryopreserved ram sperm have not been thoroughly investigated. Therefore, this study aims to assess the influence of IL-6 on the sperm quality of cryopreserved ram sperm. Ram semen was collected, pooled, and extended with tris-citrate soybean lecithin extender supplemented with 0, 50, 100, and 200 ng/mL of IL-6. The samples experienced a standard freezing protocol, and sperm quality, kinematic parameters, ultrastructure, and molecular docking of cryopreserved ram spermatozoa were evaluated. The results showed that sperm kinematics, viability, progressive motility, and membrane integrity were significantly enhanced by the addition of 100 or 200 ng of IL-6/mL (p < 0.05). Semen supplemented with 100 or 200 ng/mL of IL-6 also exhibited higher percentages of sperm kinematics, including DAP, DCL, DSL, VSL, VAP, VCL, and ALH, compared to other groups (p < 0.05). IL-6 supplementation enhanced acrosome integrity, and reduced caspase-3 activity in post-thawed ram spermatozoa (p < 0.05) compared to untreated group. Supplementation with IL-6 (200 ng/mL) significantly decreased oxidative biomarkers (NO, MDA, and H2O2) (p < 0.001) and improved total antioxidant capacity (p < 0.05). The percentage of sperm damage (tail, head, and midpiece) was significantly reduced by IL-6 supplementation (p < 0.05). Electron micrographs showed that supplementation with 100 or 200 ng/mL IL-6 protected acrosome stability, plasma membrane integrity, and sustained the ultrastructure integrity of cryopreserved ram spermatozoa. The docking exploration indicates a higher binding affinity with sperm function biomarkers, including caspase 3, BCL2, and PSMA6, with binding energies of - 52.30 kcal/mol, - 56.04 kcal/mol, and - 57.06 kcal/mol, respectively. In conclusion, the addition of IL-6 to the freezing extender can enhance the post-thaw quality of cryopreserved ram spermatozoa.

The Regulation of MicroRNA-21 by Interleukin-6 and Its Role in the Development of Fibrosis in Endometriotic Lesions

Endometriosis is one of the most common causes of chronic pelvic pain and infertility that affects 10% of women of reproductive age. It is currently defined as the presence of endometrial epithelial and stromal cells at ectopic sites; however, advances in endometriosis research have some authors believing that endometriosis should be re-defined as "a fibrotic condition in which endometrial stroma and epithelium can be identified". microRNAs (miRNAs) are regulatory molecules that potentially play a role in endometriotic lesion development. There is evidence that suggests that miRNAs, including microRNA-21 (miR-21), participate in fibrotic processes in different organs, including the heart, kidney, liver and lungs. The objective of this study was to understand the role of miR-21 and the mechanisms that can contribute to the development of fibrosis by determining how IL-6 regulates miR-21 expression and how this miRNA regulates the transforming growth factor beta (TGF-β) signaling pathway to promote fibrosis. We investigated the expression of miR-21 in the baboon and mouse model of endometriosis and its correlation with fibrosis. We demonstrated that inflammation and fibrosis are present at a very early stage of endometriosis and that the inflammatory environment in the peritoneal cavity, which includes interleukin 6 (IL-6), can regulate the expression of miR-21 in vitro and in vivo.

Follicular Fluid and Blood Monitorization of Infertility Biomarkers in Women with Endometriosis

Infertility is recognized globally as a social disease and a growing medical condition, posing a significant challenge to modern reproductive health. Endometriosis, the third-most frequent gynecologic disorder, is one of the most common and intricate conditions that can lead to female infertility. Despite extensive research, the etiology, malignant transformation, and biological therapy of endometriosis remain unknown. Blood and follicular fluid are two matrices that have been carefully studied and can provide insights into women's health. These matrices are clinically significant because they contain metabolites closely associated with women's illness stage and reproductive outcomes. Nowadays, the application of metabolomic analysis in biological matrices may be able to predict the outcome of assisted reproductive technologies with greater precision. From a molecular viewpoint on reproductive health, we evaluate and compare the utilization of human follicular fluid and blood as matrices in analysis for diagnostic and assisted reproductive technology (ART) predictors of success for endometriosis patients. In the follicular fluid (FF), plasma, and serum of endometriosis-affected women, researchers identified dysregulations of oxidative stress, upregulation of several immune factors, and aberrations in energy metabolic pathways. The altered signatures negatively correlate with the overall oocyte and embryo quality and fertilization rate.

Cytokine and chemokine profiles in women with endometriosis, polycystic ovary syndrome, and unexplained infertility

Numerous factors (including immunological, congenital, hormonal, and morphological disorders) can lead to infertility. In this regard, 3 specific diseases associated with infertility are discussed in this review study (i.e., polycystic ovary syndrome [PCOS], endometriosis [EMS], and unexplained infertility [UI]). PCOS is a common endocrine disorder characterized by chronic low-grade inflammation, and EMS is a benign disease characterized by the presence of ectopic endometrial tissue. UI refers to couples who are unable to conceive for no known reason. Conception and pregnancy are significantly affected by the immune system; in this regard, chemokines and cytokines play important roles in the regulation of immune responses. Patients with PCOS, EMS, and UI have altered cytokine and chemokine profiles, suggesting that dysregulation of these molecules may contribute to infertility in these conditions. Accordingly, the issue of infertility is addressed in this review study, a condition that affects approximately 16% of couples worldwide.

Chronic low-grade inflammation and ovarian dysfunction in women with polycystic ovarian syndrome, endometriosis, and aging

The ovarian microenvironment is critical for follicular development and oocyte maturation. Maternal conditions, including polycystic ovary syndrome (PCOS), endometriosis, and aging, may compromise the ovarian microenvironment, follicular development, and oocyte quality. Chronic low-grade inflammation can induce oxidative stress and tissue fibrosis in the ovary. In PCOS, endometriosis, and aging, pro-inflammatory cytokine levels are often elevated in follicular fluids. In women with obesity and PCOS, hyperandrogenemia and insulin resistance induce ovarian chronic low-grade inflammation, thereby disrupting follicular development by increasing oxidative stress. In endometriosis, ovarian endometrioma-derived iron overload can induce chronic inflammation and oxidative stress, leading to ovarian ferroptosis and fibrosis. In inflammatory aging (inflammaging), senescent cells may secrete senescence-associated secretory phenotype factors, causing chronic inflammation and oxidative stress in the ovary. Therefore, controlling chronic low-grade inflammation and fibrosis in the ovary would present a novel therapeutic strategy for improving the follicular microenvironment and minimizing ovarian dysfunction.

The Pathological Role of miRNAs in Endometriosis

Association studies investigating miRNA in relation to diseases have consistently shown significant alterations in miRNA expression, particularly within inflammatory pathways, where they regulate inflammatory cytokines, transcription factors (such as NF-κB, STAT3, HIF1α), and inflammatory proteins (including COX-2 and iNOS). Given that endometriosis (EMS) is characterized as an inflammatory disease, albeit one influenced by estrogen levels, it is natural to speculate about the connection between EMS and miRNA. Recent research has indeed confirmed alterations in the expression levels of numerous microRNAs (miRNAs) in both endometriotic lesions and the eutopic endometrium of women with EMS, when compared to healthy controls. The undeniable association of miRNAs with EMS hints at the emergence of a new era in the study of miRNA in the context of EMS. This article reviews the advancements made in understanding the pathological role of miRNA in EMS and its association with EMS-associated infertility. These findings contribute to the ongoing pursuit of developing miRNA-based therapeutics and diagnostic markers for EMS.

Influencing of serum inflammatory factors on IVF/ICSI outcomes among PCOS patients with different BMI

Introduction

Overweight and obese are important factors leading to the occurrence of long-term complications in women with polycystic ovary syndrome (PCOS). There has been controversy over whether dissatisfaction with pregnancy outcomes in PCOS patients is influenced by chronic inflammatory status or obesity. This retrospective study analyzed the levels of inflammatory factors in PCOS patients with different body mass index (BMI) groups and effective predictors of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) pregnancy outcomes.

Methods

There were 273 women with PCOS diagnosed who completed serum inflammatory factors test between January 2017 and June 2022 were selected. The data of 7,649 infertility PCOS patients who received their first IVF/ICSI treatment in the Reproductive Center of Peking University Third Hospital during the period of the study were collected. Finally, 92 PCOS patients were included in the high BMI group, while 97 patients were included in the normal BMI group. Baseline characteristics were collected and the pregnancy outcomes were compared among the two groups. Then, serum inflammatory factors' effect on IVF/ICSI pregnancy outcomes were analyzed with age, anti-Mullerian Hormone (AMH) and BMI adjusted.

Results

PCOS patients in the high BMI group significantly had a lower number of oocytes retrieved and good quality embryos. The high BMI group PCOS patients had higher levels of IL-6 and lower cumulative clinical pregnancy and live birth rates. The level of GM-CSF was higher in the first cycle transfer and cumulative miscarriage group. High TNF-α was negatively correlated with the first transfer cycle and cumulative clinical pregnancy rates after age, AMH and high BMI adjusted. In addition, the cumulative live birth rate was negatively correlated with high IL-6, but the first cycle transfer and cumulative live birth rates were positively correlated with high IL-1β.

Discussion

For PCOS patients, in addition to BMI, attention should also be paid to inflammatory indicators. High levels of TNF-α and IL-6 were negatively correlated with pregnancy outcomes, but high IL-1β was positively correlated with live birth rates among PCOS patients. The level of GM-CSF was higher in miscarriage PCOS patients.

Exploring the Impact of Endometrioma Aspiration and Dienogest Combination Therapy on Cyst Size, Inflammatory Cytokines in Follicular Fluid and Fertility Outcomes

Endometriomas (chocolate cysts) are cystic lesions that can develop on ovaries, and are characterized by the presence of ectopic endometrial tissue or similar tissue. Such lesions can cause a decline in the number and quality of oocytes, and lead to implantation failure. In this study, we retrospectively assessed the efficacy of repeated endometrioma aspiration and dienogest combination therapy in patients suffering endometriosis-associated infertility with endometriomas. A comparison was made between a treated group that underwent combination therapy followed by controlled ovarian hyperstimulation (COH) (n = 30) and a control group that did not undergo treatment (n = 40), at the IVF Osaka Clinic from September 2019 to September 2021. There were no differences in patient background between the two groups. A reduction in endometrioma size continued for 12 months after treatment. The numbers of follicles that developed to 15 mm or greater in size following COH and mature oocytes were significantly lower in the treated group compared to those in the control group. The levels of inflammatory cytokines in the follicular fluid significantly decreased in the treated group (p < 0.05). In patients in the treated group who underwent a second ova retrieval, the results were compared between those in the first ova retrieval (immediately after the end of treatment) and those in the second ova retrieval (four months after the first retrieval). The numbers of follicles following COH, retrieved, mature and fertilized ova were significantly increased in the second ova retrieval.

Interleukin-6 as A Useful Predictor of Endometriosis-Associated Infertility: A Systematic Review

Endometriosis is a chronic inflammatory disease defined by the presence of endometrial-like tissue outside the uterine cavity. Several authors have reported on the association between changes in inflammatory marker levels and the maintenance or progression of endometriosis and associated infertility. Interleukin-6 (IL-6) is the most studied cytokine in endometriosis and has important functions in reproductive physiology. The aim of this study is to review systematically available evidence about altered IL-6 concentrations in endometriosis-related infertility. This is a systematic review including all studies until December 2022 in which IL-6 in serum, peritoneal fluid, follicular fluid, or endometrial biopsy specimens was measured and that correlated their findings with endometriosis- associated infertility. Fifteen studies were included in the systematic review. There seems to be a correlation between elevated serum and peritoneal fluid IL-6 concentrations and the occurrence of endometriosis-associated infertility. IL-6 may be a potential diagnostic or biomarker tool for the prediction of endometriosis-related infertility. However, the numerous biases affecting the available studies, and challenges in endometriosis research reproducibility must be considered. Future investigations should pay attention to factors that may affect the results, such as the choice of suitable control groups, and carefully consider other pathological conditions affecting the patients, endometriosis stage, and type of lesion.

Decreased Expression of EZH2 in Granulosa Cells Contributes to Endometriosis-Associated Infertility by Targeting IL-1R2

The mechanism by which endometriosis, a common gynecological disease characterized by chronic pelvic pain and infertility, causes infertility remains elusive. Luteinized unruptured follicle syndrome, the most common type of ovulatory dysfunction, is a cause of endometriosis-associated infertility involving reduced numbers of retrieved and mature oocytes. Ovulation is controlled by luteinizing hormone and paracrine signals produced within the follicle microenvironment. Generally, interleukin (IL)-1β is elevated in endometriosis follicular fluid, whereby it amplifies ovulation signals by activating extracellular-regulated kinase 1/2 and CCAAT/enhancer binding protein β pathways. However, this amplification of ovulation by IL-1β does not occur in patients with endometriosis. To illuminate the mechanism of ovulatory dysfunction in endometriosis, we analyzed the effect of oxidative stress and IL-1β expression on endometriosis follicles. We found that oxidative stress decreased EZH2 expression and reduced H3K27Me3 levels in endometriosis ovarian granulosa cells (GCs). Selective Ezh2 depletion in mice ovarian GCs reduced fertility by disturbing cumulus-oocyte complex expansion and reducing epidermal growth factor-like factor expression. Gene expression and H3K27Me3 ChIP-sequencing (ChIP-Seq) of GCs revealed IL-1 receptor 2 (IL-1R2), a high-affinity IL-1β-receptor that suppresses IL-1β-mediated inflammatory cascades during ovulation, as a crucial target gene of the EZH2-H3K27Me3 axis. Moreover, IL-1β addition did not restore ovulation upon Ezh2 knockdown, indicating a vital function of IL-1R2 in endometriosis. Thus, our findings show that reducing EZH2 and H3K27Me3 in GCs suppressed ovulatory signals by increasing IL-1R2 expression, which may ultimately contribute to endometriosis-associated infertility.

Polycystic Ovary Syndrome Develops the Complications of Assisted Reproductive Technologies

Ovarian hyperstimulation syndrome (OHSS) is a serious complication that remains a threat to every patient experiencing stimulation of ovulation. Polycystic ovary syndrome (PCOS) appears to be the most important predisposing factor for OHSS. The severity of OHSS is associated with the degree of the follicular response to the ovulation inducing agents. The objective of this study was to investigate the relationship between PCOS with the risk of moderate-to-severe OHSS in intracytoplasmic sperm injection treatment patients. Sixty patients in the reproductive ages (20-38), including OHSS patients and age-matched normoresponders were included in this study. Patients who had larger follicle counts on the day of hCG injection were considered at risk for developing moderate-to-severe OHSS. In addition, oocyte quality was assessed about 20-30 min after oocyte pickup. The incidence of OHSS in PCOS patients increased significantly up to 13.9 times higher than in patients without PCOS (OR=13.900; P=0.007). Moreover, moderate-to-severe OHSS increased significantly (OR=3.860; P=0.043) in patients with primary infertility than those with secondary infertility. In addition, oocyte quality was not affected with the severity of OHSS. In conclusion, the risk of moderate-to-severe OHSS is correlated with PCOS and primary infertility without affecting oocyte quality.

IL-6 of follicular fluid and outcome of in vitro fertilization

The quality of an oocyte is influenced by its microenvironment, which includes cumulus cells and follicular fluid, as well as cells of the immune system and their products. The ovarian interleukins, which are secreted by the granulosa cells and other immune cells within the ovaries and follicles, regulate various functions between the cells. IL-6 is a cytokine that is present in the follicular fluid and may affect the quality of oocytes. There are some inconsistencies in the literature regarding the concentration of interleukin 6 in the follicular fluid. The main objective of this study was to examine whether the concentration of interleukin 6 in the follicular fluid affects the outcome of IVF. This study involved 83 patients who underwent IVF. Follicular fluid was used as the biological material for the analysis. Examination of the obtained follicular fluid and collection of oocytes under a stereomicroscope was performed in the embryological laboratory. The concentration of IL-6 in the follicular fluid was analyzed. IVF and ICSI methods were used as the fertilization methods. Pregnancy was confirmed by the positive serum β-hCG level. The software package SPSS 20 was used for statistical data processing. Analysis of the follicular fluid samples showed a correlation between the concentration of IL-6 in the follicular fluid and the outcome of IVF. The concentration of IL-6 in the follicular fluid was higher in patients with confirmed pregnancy (9.55 ± 7.47 ng/ml). Based on our results, we conclude that the concentration of IL-6 affects the outcome of IVF. If the range of IL-6 concentration is between 3,67 ng/ml and 10 ng/ml, we can expect good IVF outcome with vital pregnancy.

Follicular Fluid Growth Factors and Interleukin Profiling as Potential Predictors of IVF Outcomes

Growth hormone (GH) has gained attention as an anti-aging compound enhancing oocyte quality. In fact, GH is known to activate intrafollicular metabolic events for oocyte maturation. Insulin growth factor I (IGF1) is another ovarian growth factor that mediates the FSH and GH actions. Cytokines could also increase IVF outcomes. Indeed, IL-6 is a pleiotropic cytokine with multiple cellular effects that can vary based on the physiological environment. IL-6 may also play an important role in follicular development (Yang et al., J Assist Reprod Genet, 2020, 37 (5), 1171–1176). Clinical studies have been performed to explore the potential role of IL-6 in human oocyte maturation and subsequent embryonic development. To date, the answers are not conclusive. During peri-implantation, many cytokines balances are regulated like pro-inflammatory and anti-inflammatory interleukins. The pro-inflammatory properties of IL-17 and its impact on the tumor microenvironment or autoimmune diseases are characterized, but new dimensions of IL-17 activity that promotes embryo implantation are not well explored. In the search for answers, our study compared concentrations of growth factors IGF1, GH, and interleukins IL-6 and IL-17 in the follicular fluid (FF) from 140 women divided into two groups depending on bad (G1) or good prognosis (G2) and investigated the relationships between these FF components’ levels and the main parameters of IVF. GH, IGF1, and IL-6 were significantly higher for G2. For GH, it was negatively correlated to patient age and positively correlated to maturity rate and IGF1. Moreover, GH and IGF1 were correlated to the top embryo rate and cumulative pregnancy rate. Regarding IL-6, it was correlated to IGF1 level, endometrium thickness, and implantation rate. As for IL-17, it was only correlated to IL-6. Consequently, all these FF components were predictive of oocyte quality except IL-17. GH seemed to be the best biomarker of this quality.

Endometriosis Is Undervalued: A Call to Action

Endometriosis is an inflammatory chronic pain condition caused by uterine tissue growing outside of the uterus that afflicts at least 11% of women (and people assigned female at birth) worldwide. This condition results in a substantial burden to these women, and society at large. Although endometriosis was first identified over 160 years ago, substantial knowledge gaps remain, including confirmation of the disease's etiology. Research funding for endometriosis is limited, with funding from bodies like the National Institutes of Health (NIH) constituting only 0.038% of the 2022 health budget—for a condition that affects 6.5 million women in the US alone and over 190 million worldwide. A major issue is that diagnosis of endometriosis is frequently delayed because surgery is required to histologically confirm the diagnosis. This delay increases symptom intensity, the risk of central and peripheral sensitization and the costs of the disease for the patient and their nation. Current conservative treatments of presumed endometriosis are pain management and birth control. Both of these methods are flawed and can be entirely ineffective for the reduction of patient suffering or improving ability to work, and neither addresses the severe infertility issues or higher risk of certain cancers. Endometriosis research deserves the funding and attention that befits a disease with its substantial prevalence, effects, and economic costs. This funding could improve patient outcomes by introducing less invasive and more timely methods for diagnosis and treatment, including options such as novel biomarkers, nanomedicine, and microbiome alterations.

Altered p16Ink4a, IL-1β, and Lamin b1 Protein Expression Suggest Cellular Senescence in Deep Endometriotic Lesions

Endometriosis causes immunological and cellular alterations. Endometriosis lesions have lower levels of lamin b1 than the endometrium. Moreover, high levels of pro-inflammatory markers are observed in the peritoneal fluid, follicular fluid, and serum in endometriosis lesions. Thus, we hypothesized that the accumulation of senescent cells in endometriosis tissues would facilitate endometriosis maintenance in an inflammatory microenvironment. To study senescent cell markers and the senescence-associated secretory phenotype (SASP) in endometriosis lesions, we conducted a cross-sectional study with 27 patients undergoing video laparoscopy for endometriosis resection and 19 patients without endometriosis. Endometriosis lesions were collected from patients with endometriosis, while eutopic endometrium was collected from patients both with and without endometriosis. Tissues were evaluated for senescence markers (p16Ink4a, lamin b1, and IL-1β) and interleukin concentrations. The expression of p16Ink4a increased in lesions compared to that in eutopic endometrium from endometriosis patients in the secretory phase. In the proliferative phase, lesions exhibited lower lamin b1 expression but higher IL-4 expression than the eutopic endometrium. Further, IL-1β levels were higher in the lesions than in the eutopic endometrium in both the secretory and proliferative phases. We believe that our findings may provide targets for better therapeutic interventions to alleviate the symptoms of endometriosis.

Exploring Epithelial-Mesenchymal Transition Signals in Endometriosis Diagnosis and In Vitro Fertilization Outcomes

Endometriosis (EMS) pathogenesis has been related to the release of inflammatory mediators in peritoneal fluid, creating an altered microenvironment that leads to low-grade oocyte/embryos and to the reduction of implantation rates. The Epithelial–Mesenchymal Transition (EMT), an inflammation-related process, can be a further contributing factor to EMS. This study aimed to investigate, among various cytokines and EMT markers (Cadherins, TGF-β, HIF-1α), diagnostic markers of EMS and prognostic factors of in vitro fertilization (IVF) outcomes. Herein, EMS patients manifested higher serum levels of the inflammatory molecules IL-6, IL-8, and IL-12 and a decrease in the concentrations of the anti-inflammatory IL-10. Moreover, biochemical markers associated with the EMT process were more elevated in serum and follicular fluid (FF) of EMS patients than in controls. At the end, the number of good-quality embryos was inversely related to serum IL-6 and EMT markers. Interestingly, serum IL-6 and FF IL-10 concentrations differentiated EMS patients from controls. Finally, serum IL-8 and E-Cadherin levels, as well as FF IL-10, predicted positive IVF outcome with great accuracy. Our data confirm the pivotal role of inflammatory mediators (i.e., IL-6 and IL-10) in EMS pathogenesis and suggest that EMT-related markers are elevated in EMS patients and can be predictive of IVF outcome.

The Mechanism Exploration of Follicular Fluids on Granulose Cell Apoptosis in Endometriosis-Associated Infertility

Objective

To explore the mechanisms of follicular fluids (FFs) on granulose cell (GC) apoptosis in endometriosis-associated infertility.

Materials and Methods

60 infertile women were enrolled. The FFs from 30 endometriosis-associated infertility (EI) patients were collected and processed by ELISA hormone assay and proteomic profiling. The ovary GCs collected from 30 tubal-associated infertility (TI) patients were cultured in follicular fluids of endometriosis-associated infertility patients (EI-FFs), and the apoptosis mechanisms were explored by flow cytometry assay, real-time PCR, Western blotting, and protein-protein interaction (PPI) network analysis.

Results

Our results showed that the expression of 22 specific proteins was significantly different in the FFs from EI and TI patients, and the level of testosterone and anti-Müllerian hormone was not obviously different between the two groups. EI-FFs could accelerate the apoptosis process of granulose cells of tubal-associated infertility patients (TI-GCs) by regulating the expression of 5 apoptosis-related proteins including BCL2, BAX, CASP3, CASP9, and TP53. The correlation of these 22 specific proteins and 5 apoptosis-related proteins was analyzed by PPI, and 5 protein biomarkers (INS, CXCL10, ICAM1, WIF1, and TNFRSF13C) and 5 signaling pathways (cytokine-cytokine receptor interaction, apoptosis, regulation of actin cytoskeleton, MAPK, and p53 signaling pathway) were predicted.

Conclusion

This research clarified the effect and explored the mechanisms of EI-FFs on the apoptosis of TI-GCs and indicated the protein biomarkers and signaling pathways for further study.

Pathogenesis of Endometriosis: New Insights into Prospective Therapies

Endometriosis is a female reproductive disorder characterized by growth of uterine cells and tissue in distant sites. Around 2-10% of women experience this condition during reproductive age, 35-50% of whom encounter fertility issues or pain. To date, there are no established methods for its early diagnosis and treatment, other than surgical procedures and scans. It is difficult to identify the disease at its onset, unless symptoms such as infertility and/or pain are present. Determining the mechanisms involved in its pathogenesis is vital, not only to pave the way for early identification, but also for disease management and development of less invasive but successful treatment strategies. Endometriosis is characterized by cell proliferation, propagation, evasion of immunosurveillance, and invasive metastasis. This review reports the underlying mechanisms that are individually or collectively responsible for disease establishment and evolution. Treatment of endometriosis mainly involves hormone therapies, which may be undesirable or have their own repercussions. It is therefore important to devise alternative strategies that are both effective and cause fewer side effects. Use of phytochemicals may be one of them. This review focuses on pharmacological inhibitors that can be therapeutically investigated in terms of their effects on signaling pathways and/or mechanisms involved in the pathogenesis of endometriosis.

Traditional uses, phytochemistry and pharmacological attributes of Pterocarpus santalinus and future directions: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Pterocarpus santalinus, an ancient folk medicine, is endemic to the eastern ghats of south India, and the heartwood is prescribed since time immemorial for the mitigation of inflammatory disorders in traditional practice and ayurvedic system of medicines.

AIM OF THE STUDY

This review aims to provide collective pieces of information of the traditional uses, phytochemicals, and pharmacological facets of P. santalinus, with an intuition for promoting future research to explore its pharmaceutical potential as a therapeutic agent against modern maladies.

MATERIAL AND METHODS

Extensive literature search was performed to collate the data by using various electronic search engines. A network pharmacology-based approach is incorporated for validation of traditional claims orbiting around anti-inflammatory properties and directed its future exploration against obesity, ovarian inflammation, ovarian folliculogenesis, and inflammatory breast cancer.

RESULTS

In a nutshell, the present review encompasses the phytochemistry, pharmacology of this species intending to sensitize the scientific community for future research on this promising plant. Nearly 85 chemical constituents are reported from the plants wherein bark and leaves are enriched with the lupane and oleanane class of triterpene while sesquiterpenes and polyphenolic compounds are predominantly present in the heartwood of the plant. Although phytochemical investigations are being reported since the mid-twentieth century however there has been recent interest in the evaluation of biological activities such as anti-inflammatory, anti-oxidant, anti-cancer, anti-viral, etc. CONCLUSION: In conclusion, a systematic phytochemical analysis and pharmacological exploration in close collaboration for establishing the therapeutic potential of the chemical constituents present in P. santalinus is recommended to substantiate the traditional claims for bringing it into the mainstream pharmaceutical and commercial utilization.

Effects of bone marrow mesenchymal stem cell transplantation on tumor necrosis factor-alpha receptor 1 expression, granulosa cell apoptosis, and folliculogenesis repair in endometriosis mouse models

BACKGROUND AND AIM

Endometriosis affects the ovaries and causes a decrease in the oocyte quality during endometrial receptivity. During the development of ovarian follicles, paracrine communication occurs between granulosa cells and oocytes. This study was conducted to determine the effects of bone marrow mesenchymal stem cell transplantation on tumor necrosis factor-alpha (TNF-α) receptor 1 (TNFR1) expression, granulosa cell apoptosis, and folliculogenesis in endometriosis mouse models.

MATERIALS AND METHODS

This study involved 42 female mice, which were divided into three groups: Healthy mice (T0), endometriosis mice without transplantation (T1), and endometriosis mice with bone marrow mesenchymal stem cell transplantation (T2). The mice were injected intraperitoneally with endometrial fragments (200 μL) to become endometriosis models. On day 15, the endometriosis models received mesenchymal stem cells. Sample collection was performed on day 29. Granulosa cell apoptosis and TNFR1 expression were examined using immunohistochemical staining, and folliculogenesis was assessed using hematoxylin and eosin staining of ovary samples. The data obtained from both examinations were statistically analyzed using Statistical Package for the Social Sciences.

RESULTS

The results showed that TNFR1 expression is significantly decreased in T2 (p<0.004). The apoptosis of granulosa cells was lower in T2 (p<0.000). The primary, secondary, and graafian follicle counts in T2 were significantly increased.

CONCLUSION

Bone marrow mesenchymal stem cell transplantation in endometriosis mouse models can reduce TNFR1 expression and granulosa cell apoptosis and improve folliculogenesis.

The Effects of Endometriosis on Ovarian Functions

Infertility is a main manifestation of endometriosis, though the exact pathogenesis of endometriosis-associated infertility remains unclear. Compromised ovarian functions may be one of the causes of endometriosis related infertility. The ovarian function can be classified into three basic elements, (1) production of ovarian hormones, (2) maintenance of follicular development until ovulation, and (3) reservoir of dormant oocytes (ovarian reserve). The effects of endometriosis on ovarian hormone production and follicular development are inconclusive. Ovarian endometrioma is common phonotype of endometriosis. Development of endometrioma per se may affect ovarian reserve. Surgery for endometriomas further diminish ovarian reserve, especially women with bilateral involvement. Early intervention with surgery and/or medical treatment may be beneficial, though firm evidence is lacking. When surgery is chosen in women at reproductive age, specific techniques that spare ovarian function should be considered.

Resistin and chemerin levels in follicular fluid of infertile women with endometriosis undergoing ICSI

Chemerin and resistin are two adipocytokines involved in inflammatory processes that may paly a role in the development of endometriosis. The purpose of the current study was to examine the levels of chemerin and resistin in the follicular fluid (FF) of endometriosis patients and additionally, assess the association of FF chemerin and resistin with the severity of endometriosis and the number of mature oocyte and embryos. A total of 80 reproductive-aged women who underwent intracytoplasmic sperm injection and embryo transfer were evaluated in this study. FF samples were obtained from subjects with (n = 40) and without endometriosis (n = 40). The concentrations of chemerin and resistin were examined using ELISA. The Resistin FF level was significantly (p-value=.03) higher in women with endometriosis than women without endometriosis, while the effect size was medium (d = 0.47). There was no significant difference in Chemerin concentration between the two groups of this study. Results also showed a tendency towards the increase of FF values of resistin and chemerin in endometriosis patients with stage III-IV than stage I-II; however, this difference was not significant. No significant correlations were found between FF levels of resistin and chemerin with the number of mature oocyte and embryos. Thus, elevated FF resistin levels may be associated with endometriosis.IMPACT STATEMENTWhat is already known on this subject? To our knowledge, no studies have investigated chemerin levels in follicular fluid of infertile women with endometriosis undergoing ICSI. Although follicular fluid levels of resistin have been previously studied in endometriosis, it has not been studied yet whether its level is associated with the number of oocyte and embryos.What do the results of this study add? Our results indicate that significantly increased resistin levels in follicular fluid may be associated with the presence of endometriosis.What are the implications of these findings for clinical practice and/or further research? The findings are promising in that significantly increased resistin levels may add to the knowledge of the pathophysiology of endometriosis.

Circular RNA expression profiling and bioinformatic analysis of cumulus cells in endometriosis infertility patients

Aim: To explore the circular RNA (circRNA) profile in cumulus cells from endometriosis-associated infertility patients. Methods: The expression of circRNAs was profiled by high-throughput sequencing. Sanger sequencing was performed to identify the backsplicing site. Six candidate circRNAs and their parental genes were measured in 30 samples by quantitative reverse transcription-polymerase chainreaction (qRT-PCR). Bioinformatics analysis was performed to predict the functions. Results: A total of 55 upregulated and 41 downregulated differentially expressed circRNAs were detected. Kyoto Encyclopedia of Genes and Genomes data indicated that these target genes were mainly involved in cumulus cell growth- and differentiation-related pathways. Hsa_circ_0072391, hsa_circ_0007299 and hsa_circ_0057799 were significantly increased, and hsa_circ_001533 was significantly decreased in endometriosis-associated infertility patients. Conclusion: The differentially expressed circRNAs might be potentially involved in pathophysiology of endometriosis-associated infertility.

Endometriosis Lowers the Cumulative Live Birth Rates in IVF by Decreasing the Number of Embryos but Not Their Quality

Endometriosis and infertility are closely linked, but the underlying mechanisms are still poorly understood. This study aimed to evaluate the impact of endometriosis on in vitro fertilization (IVF) parameters, especially on embryo quality and IVF outcomes. A total of 1124 cycles with intracytoplasmic sperm injection were retrospectively evaluated, including 155 cycles with endometriosis and 969 cycles without endometriosis. Women with endometriosis had significantly lower ovarian reserve markers (AMH and AFC), regardless of previous ovarian surgery. Despite receiving significantly higher doses of exogenous gonadotropins, they had significantly fewer oocytes, mature oocytes, embryos, and top-quality embryos than women in the control group. Multivariate analysis did not reveal any association between endometriosis and the proportion of top-quality embryo (OR = 0.87; 95% CI [0.66-1.12]; p = 0.3). The implantation rate and the live birth rate per cycle were comparable between the two groups (p = 0.05), but the cumulative live births rate was significantly lower in in the endometriosis group (32.1% versus 50.7%, p = 0.001), as a consequence of the lower number of frozen embryos. In conclusion, endometriosis lowers the cumulative live birth rates by decreasing the number of embryos available to transfer, but not their quality.

Interleukin in endometriosis-associated infertility-pelvic pain: systematic review and meta-analysis

The objective is to study the significance of altered interleukin levels in endometriosis-related infertility or pelvic pain. The present systematic review and meta-analysis includes a discussion on the roles of interleukin in the physiopathology of endometriosis-associated infertility and/or pelvic pain. We included all studies in which interleukins in peritoneal fluid, follicular fluid or serum from patients were measured and that correlated the findings with either peritoneal or deep endometriosis-associated infertility or pelvic pain. For the meta-analysis, we selected studies on the following cytokines: interleukin-1 (IL-1), interleukin-6 (IL-6) and interleukin-8 (IL-8). Endometriosis is a chronic inflammatory disease. Inflammatory processes clearly participate in the etiology of endometriosis. Cytokines are mediators of inflammation, and increase in their concentration in plasma or other body fluids signals the presence and extent of tissue lesions. A number of studies have reported on the association between higher cytokine levels and progression or maintenance of endometriosis and coexisting infertility or pelvic pain. The results of the analyses support that an association exists between elevated serum IL-6 and/or IL-8 concentrations and the occurrence of endometriosis-associated infertility. Such association was not found for endometriosis-associated pain. In spite of accumulated evidence on the association of pro-inflammatory cytokines and endometriosis, it still is not clear if and how these mediators participate in the physiopathology of endometriosis-associated infertility or pelvic pain, in part due to poor quality of the evidence established in the vast majority of interleukins and challenges in endometriosis research reproducibility. In summary, the results of the analyses support that an association exists between elevated serum IL-6 and/or IL-8 concentrations and the occurrence of endometriosis-associated infertility.

REASONS FOR ENDOMETRIOSIS-ASSOCIATED INFERTILITY

This article discusses the causes and mechanisms of the occurrence of infertility in endometriosis within the framework of versions and contraversions. The magnitude of the described problem is noted not only from a medical, but also from a socio-economic perspective. Four main factors of endometriosis-associated infertility were identified: tubal-peritoneal, ovarian, embryonic and endometrial. Given the inconsistency of scientific data, the need for further research is noted.

C-reactive protein and ART outcomes: a systematic review

BACKGROUND

A dynamic balance between pro- and anti-inflammatory factors contributes to regulating human female reproduction. Chronic low-grade inflammation has been detected in several female reproductive conditions, from anovulation to embryo implantation failure. C-reactive protein (CRP) is a reliable marker of inflammation that is extensively used in clinical practice. Recent studies quantified CRP in the serum of infertile women undergoing ART and suggested its potential for the prediction of ART reproductive outcomes.

OBJECTIVE AND RATIONALE

The first objective of this systematic review of the available literature was to evaluate the association between pre-implantation circulating CRP concentration and pregnancy rates in women undergoing ART. The second objective was to describe serum CRP concentration changes after early embryo implantation. The changes in circulating CRP throughout the ART cycle, clinical implications of CRP quantification for the management of women undergoing ART, and future therapeutic options will also be discussed.

SEARCH METHODS

The MEDLINE database was systematically searched from inception to March 2019 using the following key words: (C-reactive protein) AND (assisted reproductive techniques OR ovulation induction OR insemination OR in vitro fertilization). Only articles in English were considered. Studies were selected based on title and abstract. The full text of potentially relevant articles was retrieved and assessed for inclusion by two reviewers (S.B. and S.H.). The protocol was registered in the International prospective register of systematic reviews (PROSPERO; registration number: CRD148687).

OUTCOMES

In total, 10 studies were included in this systematic review. Most of these studies reported lower circulating CRP values before the window of implantation and higher circulating CRP values during the peri-implantation period in women with successful ART outcome (biochemical or clinical pregnancy) compared to women without a successful outcome. Several lifestyle factors and/or drugs that reduce the concentration of circulating CRP significantly improve ART outcomes. Subgroup analyses according to female BMI and baseline circulating CRP concentration are highly recommended in future analyses.

WIDER IMPLICATIONS

These findings highlight a possible detrimental impact of preconception high circulating CRP concentration on ART outcomes. However, the biochemical or clinical pregnancy rate endpoints used in the studies examined here are insufficient (there were no data on live birth outcome), and the impact of major variables that can influence CRP and/or ART, for example maternal age, BMI, number of transferred embryos, and use of anti-inflammatory drugs, were not considered in the analyses. CRP quantification may be a potential marker of ART outcome, but its predictive value still needs to be investigated in large prospective studies. In future, the quantification of circulating CRP before starting ART could help to identify patients with a poor ART prognosis, leading to ART cycle cancellation or to preconception treatment to minimize the medical risks and costs.

Interleukin 6 in follicular fluid reduces embryo fragmentation and improves the clinical pregnancy rate

PURPOSE

The aim of this study was to evaluate the role of interleukin 6 in embryo development in the in vitro fertilization cycles.

METHODS

This was a retrospective cohort study. One hundred and three women undergoing in vitro fertilization and embryo transfer due to a tubal factor were included in the study. The follicular fluid IL-6 levels on oocyte retrieval day from each patient were determined by ELISA. The relationships between follicular fluid IL-6 levels and IVF cycle parameters were investigated.

RESULTS

The levels of follicular fluid IL-6 were not affected by the use of drugs for superovulation or by estrogen. In addition, follicular fluid IL-6 levels did not affect the number of oocytes retrieved or the MII oocyte rate. High levels of follicular fluid IL-6 correlated with a significant increase in the rates of clinical pregnancy. Follicular fluid IL-6 levels did not affect the cell number or the blastomere symmetry of day 3 embryos, but it did significantly reduce the embryo fragmentation rate.

CONCLUSIONS

High levels of follicular fluid IL-6 improved the rates of clinical pregnancy and reduce embryo fragmentation.

Elevated Levels of Monocyte Chemotactic Protein-1 in the Follicular Fluid Reveals Different Populations among Women with Severe Endometriosis

To determine if a modification of the cytokine profile occurs in the follicular fluid (FF) of women with endometriosis undergoing in vitro fertilization (IVF), we performed a prospective observational study from January 2018 to February 2019. In total, 87 women undergoing IVF were included: 43 for severe endometriosis-related infertility and 40 controls with other causes of infertility. The cytokine profile of the FF was determined by multiplex fluorescent-bead-based technology allowing the measurement of 59 cytokines. Monocyte Chemoattractant Protein 1 (MCP-1) was the only variable retained in the multivariate analysis. We identified two subgroups of patients in the endometriosis group: MCP-1-low group (n = 23), which had FF MCP-1 levels comparable to the control group, and MCP-1-high (n = 20), which had significantly higher FF levels. Only patients in the MCP-1-high group had a significantly altered cytokine profile in the FF, and had a significantly higher serum estradiol level (p = 0.002) and a significantly lower number of oocytes recovered (p = 0.01) compared to the MCP-1-low and the control group. Our study has shown an alteration of the oocyte microenvironment in women with endometriosis associated with high follicular fluid levels of MCP-1, allowing the identification of a subgroup of endometriosis patients with a potentially worse prognosis.

Endometrioma, the follicular fluid inflammatory network and its association with oocyte and embryo characteristics

RESEARCH QUESTION

What is the association between endometrioma-affected ovaries, their follicular fluid inflammatory microenvironment, and ovary-specific oocyte and embryo yield and quality?

DESIGN

Exposure-matched prospective cohort study conducted at a university-affiliated infertility clinic. Thirty-four women presenting for oocyte retrieval were enrolled between 2012 and 2013: women with unilateral endometrioma and no other observed peritoneal or deep lesions (n = 10) and women with no signs or symptoms of endometriosis (n = 24). Follicular fluid was aspirated at the time of oocyte retrieval. Samples from each ovary were analysed using a 27-plex immunoassay panel. The associations were evaluated by ovary-specific endometrioma exposure status (affected, unaffected, unexposed) with cytokine levels, oocyte yield and embryo quality.

RESULTS

Levels of interleukin (IL)-8 and monocyte chemoattractant protein-1 were higher in fluid obtained from endometrioma-affected ovaries compared with the unexposed ovaries from women without endometriosis, with intermediate levels observed in the contralateral unaffected ovaries. More modest differences were observed for IL-1β and IL-6. The affected ovaries of women with endometriosis yielded fewer oocytes (mean ± SD = 4.6 ± 2.3) compared with both the unaffected (6.0 ± 3.8) and unexposed (7.9 ± 5.6) ovaries. After adjusting for potential confounders and variables generated in a cytokine principal components analysis, oocyte yield remained slightly lower for the endometrioma-affected ovaries compared with unexposed ovaries. No informative differences among ovary groups for embryo quality parameters were observed.

CONCLUSIONS

The results suggest that the inflammatory milieu of ovarian endometriosis is strongly localized and has a more modestly systemic effect. The effect of endometriomas on infertility, however, cannot be entirely explained by increased inflammation.

Ethiopathogenic mechanisms of endometriosis-related infertility

Endometriosis is a highly prevalent disease among women of reproductive age and is frequently associated to infertility. However, the mechanisms underlying endometriosis-related infertility are still not completely known. Several studies have been conducted in order to elucidate this question. Besides anatomical changes that may impair gametes and embryo transport along the tubes; a smaller ovarian reserve due to advanced endometriosis and endometriomas; and a dysregulated hypothalamic-pituitary-ovarian axis, there are pieces of evidence suggesting that the peritoneal ectopic endometrial foci may induce a local inflammatory response, with the recruitment of macrophages, cytokine release, and reactive oxygen species generation, leading to a pro-oxidant peritoneal microenvironment. These alterations may be systemically reflected and also affect the follicular microenvironment. A harmful follicular fluid may disrupt cumulus cells functions and, consequently, compromise oocyte competence. There is also evidence suggesting that the peritoneal fluid of women with endometriosis may alter sperm function. Reduced endometrial receptivity is also pointed as a possible mechanism involved in endometriosis-related infertility, which needs further investigation.

It Is Necessary to Purpose an Add-on to the American Classification of Endometriosis? This Disease Can Be Compared to a Malignant Proliferation While Remaining Benign in Most Cases. EndoGram® Is a New Profile Witness of Its Evolutionary Potential

Endometriosis is a curious pathology that has been the topic of many international publications. Its etiology remains mysterious but seems to have multiple causes. It is a complex disease whose lesions are very heterogeneous in where they can occur (deep endometriosis, superficial, ovarian cyst), extent, associated symptoms, evolution or aggressiveness of the disease, and response to treatments. Furthermore, it evolves in pushes, remains autonomous, and is responsible for both superficial and deep lesions that explain its two most well know challenges: pain and infertility. It has always been classified by the size of its anatomical lesions—Acosta classification (1), revised by the American fertility society (AFS) (2), and the American society of reproductive medicine (ASRM) classification with a description of the disease at different stages: minimal (score of 1 to 5), mild (3–12), moderate (16 to 40), and severe (>40) (13). If this classification provides a complete repertoire of implants (anatomic) (10), the attribution of points is arbitrary. In fact, the size of the lesions is not synonymous with the difficulty to treat them surgically. Their location, if deep, is larger than the size of ovarian endometriomas. In addition, small anatomical but evaluative lesions will have a larger impact than big fibrous and stable lesions (Figure 1). Thus, attempts to explain their inflammatory side effects have been proposed (14, 15). The French classification nodule, ovaries, adhesions, tube, and inflammation (FOATI) (10) has had the merit of taking this phenomenon into account. In our opinion, we must go much further and propose an amendment in this classification, taking into account the evolution of the lesions and their deep molecular biology because in reality, the lesions are not at the same stage.

Comprehensive immune complexome analysis detects disease-specific immune complex antigens in seminal plasma and follicular fluids derived from infertile men and women

BACKGROUND

Autoimmune reactions and subsequent inflammation may underlie spermatogenic dysfunction and endometriosis-related infertility. The aim of this study is to identify disease-specific antigens in immune complexes (ICs) in seminal plasma (SP) and in follicular fluid (FF).

METHODS

Immune complexome analysis, in which nano-liquid chromatography-tandem mass spectrometry is employed to comprehensively identify antigens incorporated into ICs in biological fluids, was performed for specimens collected from infertile couples undergoing assisted reproduction. Forty-two male patients consisting of subjects with oligozoospermia (n = 6), asthenozoospermia (n = 8), and normal semen analysis (n = 28). Fifty-eight female patients consisting of subjects with ovarian endometriosis (n = 10) and control women without disease (n = 48).

RESULTS

Four disease-specific antigens were identified in subjects with oligozoospermia, while five disease-specific antigens were detected in subjects with asthenozoospermia, some of which are involved in sprematogenesis. Eight antigens were detected only in subjects with endometriosis.

CONCLUSION

Functional characteristics of disease-specific antigens were found to correspond to the pathogenesis of male and female infertility. The formation of ICs may contribute to spermatogenic dysfunction and endometriosis-related infertility via loss of function of the related proteins. Immune complexome analysis is expected to be a valuable tool for the investigation of novel diagnostic methods and treatment strategies for infertility.

Chronic Niche Inflammation in Endometriosis-Associated Infertility: Current Understanding and Future Therapeutic Strategies

Endometriosis is an estrogen-dependent inflammatory disease that affects up to 10% of women of reproductive age and accounts for up to 50% of female infertility cases. It has been highly associated with poorer outcomes of assisted reproductive technology (ART), including decreased oocyte retrieval, lower implantation, and pregnancy rates. A better understanding of the pathogenesis of endometriosis-associated infertility is crucial for improving infertility treatment outcomes. Current theories regarding how endometriosis reduces fertility include anatomical distortion, ovulatory dysfunction, and niche inflammation-associated peritoneal or implantation defects. This review will survey the latest evidence on the role of inflammatory niche in the peritoneal cavity, ovaries, and uterus of endometriosis patients. Nonhormone treatment strategies that target these inflammation processes are also included. Furthermore, mesenchymal stem cell-based therapies are highlighted for potential endometriosis treatment because of their immunomodulatory effects and tropism toward inflamed lesion foci. Potential applications of stem cell therapy in treatment of endometriosis-associated infertility in particular for safety and efficacy are discussed.

Interleukin 15 concentrations in follicular fluid and their effect on oocyte maturation in subfertile women undergoing intracytoplasmic sperm injection

PURPOSE

To calculate the concentrations of interleukin 15 (IL-15) in follicular fluid (FF) and evaluate their relation with oocyte maturation, follicle size, and patients' body mass index (BMI) and age.

METHODS

Follicular fluid specimens were obtained from 56 subfertile women undergoing intracytoplasmic sperm injection (ICSI) during oocyte retrieval for measurement of IL-15 concentrations with ELISA. Wilcoxon's test and Pearson's correlation coefficient were used to correlate FF concentrations of IL-15 with follicular size and stage of oocyte maturation, along with patients' BMI and age.

RESULTS

IL-15 concentrations in FF of follicles with immature oocytes were significantly greater than those from follicles with mature ones (median 5.333 vs. 3.250 pg/ml, respectively, p < 0.001). There was a significant negative correlation between IL-15 concentrations and follicle size (r = - 0.333, p = 0.003). No significant correlation was observed between IL-15 concentrations and patients' BMI and age (p > 0.05).

CONCLUSIONS

IL-15 concentrations in FF are adversely related with the size of the follicles and the maturity of the corresponding retrieved oocytes in a cohort of expected normal responders undergoing intracytoplasmic sperm injection (ICSI). Follicular fluid concentrations of IL-15 should be investigated as a possible predictive factor for oocyte maturity.

Endometriosis Is a Cause of Infertility. Does Reactive Oxygen Damage to Gametes and Embryos Play a Key Role in the Pathogenesis of Infertility Caused by Endometriosis?

Approximately, 10-15% of women of reproductive age are affected by endometriosis, which often leads to infertility. Endometriosis often has an inherited component, and several causative predisposing factors are hypothesized to underlie the pathogenesis of endometriosis. One working hypothesis is the theory of retrograde menstruation. According to the theory of retrograde menstruation, components of refluxed blood, including apoptotic endometrial tissue, desquamated menstrual cells, lysed erythrocytes, and released iron, induce inflammation in the peritoneal cavity. This in turn activates macrophage release of reactive oxygen species (ROS), leading to oxidative stress via the respiratory burst. Refluxed blood promotes the Fenton reaction, terminating in the production of hydroxyl radical, the most potently destructive ROS. In this article, we review the papers that demonstrate decreased quantity and quality of oocytes and embryos retrieved from IVF/ICSI patients with endometriosis. We discuss literature data demonstrating that ROS are generated in endometriotic tissues that have physical proximity to gametes and embryos, and demonstrating adverse impacts on oocyte, sperm and embryo microtubule apparatus, chromosomes, and DNA. Data that addresses the notions that endometriosis causes oocyte and fetal aneuploidy and that these events are mediated by ROS species are also discussed. Literature data are also discussed that employ use of anti-oxidant molecules to evaluate the importance of ROS-mediated oxidative damage in the pathogenesis of endometriosis. Studies are discussed that have employed anti-oxidants compounds as therapeutics to improve oocyte and embryo quality in infertile subjects, and improve fertility in patients with endometriosis.

Management of Endometriomas Prior to IVF

Endometriosis causes a decrease in fertility in affected patients. The different forms of the disease, peritoneal, ovarian, deep infiltrating and adenomyosis, are often present in varying degrees in the same patient, either together or individually, and cause infertility through a pathogenesis that is not yet clear. A significant number of women with endometriosis and endometriomas will eventually seek assisted reproductive technology (ART) for conception. The specific impact of endometriomas alone and the impact of surgical intervention for endometriomas on the reproductive outcome of women undergoing in vitro fertilization/intra-cytoplasmic sperm injection (IVF/ICSI) are areas that need further clarification and, for this reason, the management of endometriomas before clinical IVF is a very complex topic.

In order to provide useful information for the clinical management of patients with endometriomas having IVF, in this review we investigated: the impact of the presence of endometriomas, both individually and associated with other types of the disease, on IVF techniques; the possible role of surgery and its possible negative effects; the risks and difficulties related to conservative management during IVF procedures.