Success rates of in vitro fertilization versus intracytoplasmic sperm injection in men with serum anti-sperm antibodies: a consecutive cohort study

Physiological and pathological aspects of epididymal sperm maturation

In mammals, sperm that leave the testes are nonfunctional and require a complex post-testicular maturation process to acquire their ability to recognize and fertilize the egg. The crucial maturation changes that provide sperm their fertilizing capability occur while passing through the epididymis. Due to the widespread use of assisted reproductive technologies to address male infertility, there has been a significant decrease in research focusing on the mechanisms underlying the maturation process over the past decades. Considering that up to 40% of male infertility is idiopathic and could be reflecting sperm maturation defects, the study of post-testicular sperm maturation will clearly contribute to a better understanding of the causes of male infertility and to the development of both new approaches to maturing sperm in vitro and safer male contraceptive methods. Based on this, the present review focuses on the physiopathology of the epididymis as well as on current approaches under investigation to improve research in sperm maturation and as potential therapeutic options for male infertility.

Anti-sperm Antibodies as an Increasing Threat to Male Fertility: Immunological Insights, Diagnostic and Therapeutic Strategies

It is a fact that sperm possess antigenic properties. Substantial scientific research suggests that specific antibodies that attach to sperm antigens can induce infertility in both humans and other species. Antisperm antibodies (ASA) represent a significant etiology of infertility in humans, leading to immunoinfertility. The association between ASA and infertility is multifaceted. The observation of sperm agglutination, although not conclusive for the diagnosis of immunological infertility, may suggest the presence of ASA. Nevertheless, ASA may also manifest in the lack of any sperm agglutination. Managing ASA from an andrological perspective depends on the underlying cause and the specific approaches healthcare professionals adopt. The precise etiology of male infertility resulting from ASA remains unclear. Current research has examined the impact of ASA and its prevalence among infertile males to understand the relationship between ASA and changes in semen parameters. However, the findings have been inconclusive. Numerous techniques have been documented for the management of immunoinfertility. This review examines the importance of ASA in the context of infertility, encompassing the postulated mechanisms underlying the development of ASA, the various assays employed for detecting them, and the available treatments.

Update on the research on the antigens of anti-sperm antibodies over the last decade

This review summarizes the advancements over a decade of research on antigens of anti-sperm antibodies (ASAs), which are key to male immune infertility. Despite the progress in assisted reproductive technologies, understanding the roles and mechanisms of ASAs and their antigens remains vital for immune infertility management. We conducted a comprehensive literature search on PubMed from January 2013 to December 2023 using the following keywords: "anti-sperm antibody," "sperm antigen," and "immune infertility." In this review, we focus on the discoveries in sperm antigen identification and characterization through proteomics, gene disruption technology, and immunoinformatics, along with the development of fertility biomarkers. Here, we discuss the clinical applications of improved ASA detection methods and the progress in the development of immunocontraceptive vaccines. The intersection of advanced diagnostic techniques and vaccine development represents a promising frontier in reproductive health. The findings also highlight the need for standardized ASA detection methods and a comprehensive molecular-level approach to understanding ASA-related infertility. These insights underscore the significance of ongoing reproductive immunology research in enhancing clinical fertility outcomes and contraceptive vaccine development.

Emerging arguments for reproductive technologies in wildlife and their implications for assisted reproduction and conservation of threatened marsupials

Assisted reproductive technologies (ARTs) have significant potential to make a meaningful contribution to the conservation of threatened wildlife. This is true of Australia's iconic, and endangered koala (Phascolarctos cinereus). If developed, ARTs could offer a solution to manage genetic diversity and costs in breeding programs and may provide frozen repositories for either insurance or the practical production of genetically resilient koalas for release and on-ground recovery. Holding back the wider use of ARTs for koalas and other wildlife is a lack of funding to close the remaining knowledge gaps in the marsupial reproductive sciences and develop the reproductive tools needed. This lack of funding is arguably driven by a poor understanding of the potential contribution ARTs could make to threatened species management. We present a review of our cross-disciplinary and accessible strategy to draw much needed public attention and funding for the development of ARTs in wildlife, using emerging cost and genetic modelling arguments and the koala as a case study.

Therapeutic approaches for anti-sperm-antibodies in the testicular sperm aspiration rat model

Background and Aim: Anti-sperm antibodies (ASAs) treatment continued to be neglected. This study aimed to generate ASAs using the testicular sperm aspiration (TSA) rat model, which allowed for investigation of four distinct therapeutic approaches to find potential treatments for ASAs. Materials and Methods: Adult Wistar albino male rats were divided into six equal groups (n = 12). The negative control group underwent scrotal sac surgery without having their testicles punctured. Punctures were made in the remaining 5 groups, with one group left untreated to serve as the positive control group. The remaining 4 groups were treated with either dexamethasone (DEX), azathioprine (AZA), frankincense, or anti-ASAs secondary antibodies. For 10 weeks, serum samples were collected every 2 weeks for specific quantification of ASAs. Testis and epididymis tissues were collected for histopathological analysis. Results: The ASAs concentrations of the positive controls were significantly higher (p ≤ 0.001) than their negative control counterparts during the examined weeks. However, The ASAs indices (%) differed according to the treatment type. While the ASAs indices at the 2nd and 4th weeks in the AZA-treated group were significantly reduced compared to the positive control group (p ≤ 0.001), no significant differences were observed at any of the sample collection week for the DEX-treated rats. The ASAs indices were significantly decreased only at weeks 6 and 8 of treatment in the frankincense-treated group (p ≤ 0.001). In the secondary antibodies-treated group, the antibody indices were significantly decreased in all weeks except for samples collected at week 4 (p ≤ 0.001). The testosterone levels reverted to normal only in TSA rats treated with either Frankincense or secondary antibodies, as they were significantly higher than the positive controls (p ≤ 0.05). Tissue samples from the secondary antibody-treated rats showed a generally normal histological appearance. Conclusion: This study tried to offer realistic therapy suggestions; however, caution should be applied when extrapolating findings from experimental models to meet clinical requirements.

Impact of intracytoplasmic sperm injection in women with non-male factor infertility: A systematic review and meta-analysis

OBJECTIVE

The purpose of this study is to determine whether intracytoplasmic sperm injection (ICSI) is beneficial in patients with non-male factor infertility.

METHODS

This systematic review and meta-analysis included articles from inception to May 2022. Published studies of non-male factor infertile women undergoing ICSI or in vitro fertilization (IVF) included in PubMed, Embase, web of science, Wanfang Database, and CNKI were searched by computer, without language restrictions. A random-effect model was applied to calculate the risk ratios (RRs) and their 95% confidence intervals (CIs). Letters, case reports, and review articles including meta-analyses and expert opinions were excluded. The primary endpoints were laboratory outcomes and pregnancy outcomes. The Secondary endpoints were neonatal outcomes.

RESULTS

Six randomized controlled studies and 20 retrospective cohort studies met the inclusion criteria. In meta-analytic forest plots, compared with IVF, those who received ICSI treatment were not different in fertilization rate (RR = 0.99, 95% CI [0.90-1.09], P = 0.88), total fertilization failure rate (RR = 1.30, 95% CI [1.17-1.45], P < 0.00001), and good quality embryo rate (RR = 0.94, 95% CI [ 0.86-1.02], P = 0.15), clinical pregnancy rate (RR = 0.84, 95% CI [0.70-1.01], P = 0.06), live birth rate (RR = 0.89, 95% CI [0.77-1.03], P = 0.13), miscarriage rate (RR = 1.06, 95% CI [0.78-1.43], P = 0.71), preterm neonatal delivery rate (RR = 0.92, 95% CI [0.67-1.26], P = 0.61), and low neonatal weight rate (RR = 1.13, 95% CI [0.80-1.61], P = 0.48). However, the implantation rate of IVF was better than ICSI (RR = 0.77, 95% CI [0.64-0.93], P = 0.005). In the subgroup analysis of the live birth rate of fresh embryo transfer, IVF performed in those ≥35 years had a higher live birth rate (RR = 0.82, 95% CI [0.78-0.83], P < 0.001).

CONCLUSION

The findings of this study indicate that ICSI is not superior to IVF in the treatment of infertility related to non-male factors. In order to confirm this result, more high-quality clinical studies are needed.

Opportunities and Limits of Conventional IVF versus ICSI: It Is Time to Come off the Fence

Conventional IVF (c-IVF) is one of the most practiced assisted reproductive technology (ART) approaches used worldwide. However, in the last years, the number of c-IVF procedures has dropped dramatically in favor of intracytoplasmic sperm injection (ICSI) in cases of non-male-related infertility. In this review, we have outlined advantages and disadvantages associated with c-IVF, highlighting the essential steps governing its success, its limitations, the methodology differences among laboratories and the technical progress. In addition, we have debated recent insights into fundamental questions, including indications regarding maternal age, decreased ovarian reserve, endometriosis, autoimmunity, single oocyte retrieval-cases as well as preimplantation genetic testing cycles. The “overuse” of ICSI procedures in several clinical situations of ART has been critically discussed. These insights will provide a framework for a better understanding of opportunities associated with human c-IVF and for best practice guidelines applicability in the reproductive medicine field.

Antisperm Antibody Testing: A Comprehensive Review of Its Role in the Management of Immunological Male Infertility and Results of a Global Survey of Clinical Practices

Antisperm antibodies (ASA), as a cause of male infertility, have been detected in infertile males as early as 1954. Multiple causes of ASA production have been identified, and they are due to an abnormal exposure of mature germ cells to the immune system. ASA testing (with mixed anti-globulin reaction, and immunobead binding test) was described in the WHO manual 5th edition and is most recently listed among the extended semen tests in the WHO manual 6th edition. The relationship between ASA and infertility is somewhat complex. The presence of sperm agglutination, while insufficient to diagnose immunological infertility, may indicate the presence of ASA. However, ASA can also be present in the absence of any sperm agglutination. The andrological management of ASA depends on the etiology and individual practices of clinicians. In this article, we provide a comprehensive review of the causes of ASA production, its role in immunological male infertility, clinical indications of ASA testing, and the available therapeutic options. We also provide the details of laboratory procedures for assessment of ASA together with important measures for quality control. Additionally, laboratory and clinical scenarios are presented to guide the reader in the management of ASA and immunological male infertility. Furthermore, we report the results of a recent worldwide survey, conducted to gather information about clinical practices in the management of immunological male infertility.

Immune infertility in men

Male factors are implicated as the cause of roughly half of cases of infertility, and the presence of antisperm antibodies (ASA) may be responsible for some of these. Their presence is associated with a reduction in natural conception and live birth and impacts the success of assisted reproductive technologies. Interpretation of the data regarding ASAs and fertility is complicated by a lack of standardization in testing methodology and test thresholds and a lack of data on their prevalence in the healthy fertile population. Although their pathogenesis remains elusive, and many cases are idiopathic, a disruption in the immunologic blood-testis barrier (BTB) appears to contribute to the formation of ASA. As delineation of the specific antigen targets of ASA advances, it has been recognized that they may affect almost all aspects of sperm function, and ASA against different targets likely have specific mechanisms of impairing fertility. Intracytoplasmic sperm injection (ICSI) appears to be the most reliable method by which to overcome fertility impairment due to ASA, achieving similar outcomes to ASA-negative patients with regard to fertilization rates, embryonic development, clinical pregnancy rates, and live birth rates. The lack of consistency in testing for and reporting ASA remains a substantial barrier to achieving clarity in describing their role in infertility and the optimal management approach, and future research should use a unified approach to the detection and description of ASA. Determination of the specific antigens targeted by ASA, and their function and clinical relevance, would contribute to improving the understanding of ASA-mediated impacts on fertility and tailoring treatment appropriately to achieve the best outcomes for patients.

Pathogenesis of Autoimmune Male Infertility: Juxtacrine, Paracrine, and Endocrine Dysregulation

According to global data, there is a male reproductive potential decrease. Pathogenesis of male infertility is often associated with autoimmunity towards sperm antigens essential for fertilization. Antisperm autoantibodies (ASAs) have immobilizing and cytotoxic properties, impairing spermatogenesis, causing sperm agglutination, altering spermatozoa motility and acrosomal reaction, and thus preventing ovum fertilization. Infertility diagnosis requires a mandatory check for the ASAs. The concept of the blood-testis barrier is currently re-formulated, with an emphasis on informational paracrine and juxtacrine effects, rather than simple anatomical separation. The etiology of male infertility includes both autoimmune and non-autoimmune diseases but equally develops through autoimmune links of pathogenesis. Varicocele commonly leads to infertility due to testicular ischemic damage, venous stasis, local hyperthermia, and hypoandrogenism. However, varicocelectomy can alter the blood-testis barrier, facilitating ASAs production as well. There are contradictory data on the role of ASAs in the pathogenesis of varicocele-related infertility. Infection and inflammation both promote ASAs production due to "danger concept" mechanisms and because of antigen mimicry. Systemic pro-autoimmune influences like hyperprolactinemia, hypoandrogenism, and hypothyroidism also facilitate ASAs production. The diagnostic value of various ASAs has not yet been clearly attributed, and their cut-levels have not been determined in sera nor in ejaculate. The assessment of the autoimmunity role in the pathogenesis of male infertility is ambiguous, so the purpose of this review is to show the effects of ASAs on the pathogenesis of male infertility.

Practical Clinical and Diagnostic Pathway for the Investigation of the Infertile Couple

Capsule

This expert opinion summarizes current knowledge on risk factors for infertility and identifies a practical clinical and diagnostic approach for the male and female partners of an infertile couple aimed to improve the investigation and management of fertility problems.

Background

Infertility represents an important and growing health problem affecting up to 16% of couples worldwide. In most cases, male, female, or combined factor can be identified, and different causes or risk factors have been related to this condition. However, there are no standardized guidelines on the clinical-diagnostic approach of infertile couples and the recommendations concerning infertility are sometimes lacking, incomplete, or problematic to apply.

Objective

The aim of this work is to provide an appropriate clinical and diagnostic pathway for infertile couples designed by a multidisciplinary-team of experts. The rationale is based on the history and physical examination and then oriented on the basis of initial investigations. This approach could be applied in order to reduce variation in practice and to improve the investigation and management of fertility problems.

Methods

Prominent Italian experts of the main specialties committed in the ART procedures, including gynecologists, andrologists, embryologists, biologists, geneticists, oncologists, and microbiologists, called "InfertilItaly group", used available evidence to develop this expert position.

Outcomes

Starting from the individuation of the principal risk factors that may influence the fertility of females and males and both genders, the work group identified most appropriate procedures using a gradual approach to both partners aimed to obtain a precise diagnosis and the most effective therapeutic option, reducing invasive and occasionally redundant procedures.

Conclusions

This expert position provides current knowledge on risk factors and suggests a diagnostic workflow of infertile couples. By using this step-by-step approach, health care workers involved in ART, may individuate a practical clinical management of infertile couples shared by experts.

Thoughts on the popularity of ICSI

Purpose

Intracytoplasmic sperm injection (ICSI) is the most widely utilized assisted reproductive technique (ART) worldwide. In this feature, we review the early assisted fertilization attempts that eventually led to the development of ICSI, and discuss its current utilization in cases of male and non-male factor infertility.

Methods

We researched the literature related to the development, indications, and current use of ICSI, such as sperm structural abnormalities, male genetic indications, surgically retrieved sperm, high sperm chromatin fragmentation, oocyte dysmorphism, and preimplantation genetic testing (PGT). We also describe the potential future applications of ICSI.

Results

This review summarizes the early micromanipulation techniques that led to the inception of ICSI. We also explore its current indications, including non-male factor infertility, where its use is more controversial. Finally, we consider the benefits of future advancements in reproductive biology that may incorporate ICSI, such as in vitro spermatogenesis, neogametogenesis, and heritable genome editing.

Conclusion

The versatility, consistency, and reliability of ICSI have made it the most prevalently utilized ART procedure worldwide.

Association between X-ray repair cross-complementing group 1 Arg399Gln polymorphism and male infertility: An update meta-analysis

Numerous studies concentrate on the association between X-ray repair cross-complementing group 1 (XRCC1) gene polymorphism and male infertility; however, the results remain inconclusive and inconsistent. Hence, this meta-analysis was conducted to get a precise estimation of the correlation. PubMed, Web of Science, Embase, Scopus and China National Knowledge Infrastructure (CNKI) databases were searched to identify the all relevant studies before 3 May 2020. Summary odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to assess the strength of the association. Finally, six studies with 1,886 cases and 1,212 controls were included in our study. The result indicated that XRCC1 Arg399Gln polymorphism was significantly associated with male infertility under allelic model (A-allele vs. G-allele: OR = 1.183, p = .003), heterozygote genetic model (AA vs. GA: OR = 1.256, p = .027), recessive genetic model (AA vs. GG + GA: OR = 1.279, p = .012) and dominant genetic model (AA + GA vs. GG: OR = 1.218, p = .026). In addition, in Asian subgroup, statistic correlation remained significant in allelic model (A-allele vs. G-allele: OR = 1.145, p = .025) with rare heterogeneity (I²  = 0%). In summary, our meta-analysis suggested that XRCC1 Arg399Gln polymorphism was significantly associated with male infertility and the A-allele might be a risk factor for this disease, especially in Asians.