Andrology laboratory technique for analysis of semen in men with azoospermia

ABSTRACT

Discovery of spermatozoa during the 17 th century led to developing technologies for semen analysis in the early 1900s, and then, standard techniques were implemented during the 20 th century. Semen analysis has a pivotal role in the male infertility evaluation, and azoospermia is an important finding. Azoospermia is identified in 15% of infertile men. However, the accurate laboratory assessment of azoospermia poses certain technical challenges. Laboratories currently perform semen assessment with great variability; thus, a standard method should be used. Planning suitable management and determining the cause of infertility require a precise evaluation of azoospermia. This review aims to address the definition of azoospermia and highlight laboratory methods in the assessments of azoospermia. Basic methods such as centrifugation, repeat pellet analysis, and staining and advanced methods such as genetic testing and biomarkers have been discussed. These methods have helped in standardizing the protocol for accurate azoospermia assessments with less variability.

Diagnostic algorithm in men suspected with nonobstructive azoospermia

ABSTRACT

This review focuses on the diagnostic algorithm for nonobstructive azoospermia (NOA), a significant male factor contributing to infertility. NOA, characterized by the absence of sperm in the ejaculate, requires a systematic diagnostic approach to identify reversible conditions, genetic factors, and prognosis for achieving pregnancy. The diagnostic pathway involves semen analysis and a comprehensive evaluation for hormonal deficiencies, anatomical abnormalities, and genetic factors. The importance of medical history, physical examination, endocrine evaluation, imaging, and genetic testing is emphasized. This review highlights the significance of differentiating NOA from obstructive azoospermia (OA) and outlines key considerations for effective management, including surgical sperm retrieval and assisted reproductive techniques. Testicular biopsy is discussed as a definitive method to distinguish obstructive cases from nonobstructive cases, providing valuable prognostic information. Overall, a thorough and systematic diagnostic approach is essential for the effective management of men suspected with NOA, offering insights into potential treatment options and reproductive outcomes.

Advances in human In vitro spermatogenesis: A review

Recent advances surrounding in vitro spermatogenesis (IVS) have shown potential in creating a new paradigm of regenerative medicine in the future of fertility treatments for males experiencing non-obstructive azoospermia (NOA). Male infertility is a common condition affecting approximately 15% of couples, with azoospermia being present in 15% of infertile males (Cocuzza et al., 2013; Esteves et al., 2011a). Treatment for patients with NOA has primarily been limited to surgical sperm retrieval combined with in vitro fertilization intracytoplasmic sperm injection (IVF-ICSI); however, sperm retrieval is successful in only half of these patients, and live birth rates typically range between 10 and 25% (Aljubran et al., 2022). Therefore, a significant need exists for regenerative therapies in this patient population. IVS has been considered as a model for further understanding the molecular and cellular processes of spermatogenesis and as a potential regenerative therapeutic approach. While 2D cell cultures using human testicular cells have been attempted in previous research, lack of proper spatial arrangement limits germ cell differentiation and maturation, posing challenges for clinical application. Recent research suggests that 3D technology may have advantages for IVS due to mimicry of the native cytoarchitecture of human testicular tissue along with cell-cell communication directly or indirectly. 3D organotypic cultures, scaffolds, organoids, microfluidics, testis-on-a-chip, and bioprinting techniques have all shown potential to contribute to the technology of regenerative treatment strategies, including in vitro fertilization (IVF). Although promising, further work is needed to develop technology for successful, replicable, and safe IVS for humans. The intersection between tissue engineering, molecular biology, and reproductive medicine in IVS development allows for multidisciplinary involvement, where challenges can be overcome to realize regenerative therapies as a viable option.

Improved phenotypic classification of male infertility to promote discovery of genetic causes

An increasing number of genes are being described in the context of non-syndromic male infertility. Linking the underlying genetic causes of non-syndromic male infertility with clinical data from patients is important to establish new genotype-phenotype correlations. This process can be facilitated by using universal nomenclature, but no standardized vocabulary is available in the field of non-syndromic male infertility. The International Male Infertility Genomics Consortium aimed at filling this gap, providing a standardized vocabulary containing nomenclature based on the Human Phenotype Ontology (HPO). The "HPO tree" was substantially revised compared with the previous version and is based on the clinical work-up of infertile men, including physical examination and hormonal assessment. Some causes of male infertility can already be suspected based on the patient's clinical history, whereas in other instances, a testicular biopsy is needed for diagnosis. We assembled 49 HPO terms that are linked in a logical hierarchy and showed examples of morphological features of spermatozoa and testicular histology of infertile men with identified genetic diagnoses to describe the phenotypes. This work will help to record patients' phenotypes systematically and facilitate communication between geneticists and andrologists. Collaboration across institutions will improve the identification of patients with the same phenotypes, which will promote the discovery of novel genetic causes for non-syndromic male infertility.

Non-Invasive Diagnostics of Male Spermatogenesis from Seminal Plasma: Seminal Proteins

The compounds of seminal plasma have great potential as biomarkers of male fertility and can be used as a diagnostic tool for types of azoospermia. Azoospermia occurs in approximately 1% of the male population, and for an effective therapy of this form of male infertility, it is important to distinguish between obstructive and non-obstructive azoospermia. Proteins in seminal plasma can serve as biomarkers for diagnosing azoospermia. Considering the various types of obstructions, a combination of multiple proteins is advisable for diagnostic purposes. In this context, testicular and epididymal proteins are particularly significant, as they are specific to these tissues and typically absent in ejaculate during most obstructions. A combination of multiple biomarkers is more effective than the analysis of a single protein. This group of markers contains TEX101 and ECM1 proteins, combined detections of these two bring a diagnostic output with a high sensitivity and specificity. Similar results were observed for combined detection of TEX101 and SPAG1. The effective using of specific biomarkers from seminal plasma can significantly improve the existing approaches to diagnosis of the causes of male infertility.

IVF outcomes following ICSI cycles using testicular sperm in obstructive (OA) vs. non-obstructive azoospermia (NOA) and the impact of maternal and paternal age: a SART CORS data registry

PURPOSE

To assess the differences in IVF outcomes between couples with obstructive azoospermia (OA), non-obstructive azoospermia (NOA), and male factor (MF).

METHODS

Using the SART CORS data from 2016 to 2017, we included all initial autologous cycles with a diagnosis of male factor with ejaculated and surgically obtained sperm. We analyzed 71,121 cycles, including 3467 with a diagnosis of azoospermia and 67,654 with other non-azoospermic MF. Using a multivariate binomial regression, we estimated adjusted risk ratios comparing outcomes for ICSI cycles using surgically acquired (OA and NOA) versus ejaculated sperm (MF). Outcomes reported per initial cycle included clinical pregnancy, live birth, biochemical pregnancy, and miscarriage. Outcomes reported per singleton pregnancy included full-term delivery (≥ 37 weeks), normal birth weight (≥ 2500 g), and delivery method.

RESULTS

After frozen embryo transfers (FET), patients with NOA had 7% higher odds of live birth compared to MF (aOR 1.23 (0.94-1.74)), and those with OA had 2.6% lower chance of live birth compared to MF (aOR 0.73 (95%CI 0.5-1.05)). After fresh ET, patients with NOA had 5% higher chance of live birth (aOR 1.11 (0.9-1.36)), and those with OA had a 2.5% higher chance of live birth (aOR 1.10 (95%CI 0.89-1.34)) compared to MF. All three subgroups had lower fresh live birth rates (LBR) compared to FETs.

CONCLUSION

Couples with either NOA or OA have overall comparable ART and perinatal outcomes to couples with MF, and their success is primarily dependent on both patient's and partner's age.

Testicular Core Extraction: Important Technique for Determining Sperm Retrieval Method in Non-obstructive Azoospermia

OBJECTIVE

To assess the value of preliminary testicular core extraction (TCE) as a tool for determining whether to pursue clinic testicular extraction (cTESE) versus microscopic testicular sperm extraction (mTESE) to minimize both financial burden and procedural complexity.

METHODS

All men with non-obstructive azoospermia (NOA) from 2018 to 2022 who underwent clinic TCE were analyzed. Patients who were found to have sperm on initial TCE were recommended cTESE. Patients who did not have sperm on initial TCE were recommended for mTESE. Sensitivity, specificity, positive predictive value, and negative predictive value of TCE were calculated. Cost reductions were determined based on this institution's fees. A nonparametric Wilcoxon test was performed to determine statistical significance between the results of the TCE sperm present and sperm absent groups.

RESULTS

Of the 82 NOA patients undergoing TCE, 51 (62.2%) core biopsies were positive for sperm and 31 (37.8%) were negative for sperm. The SRR for 35 men who then underwent cTESE following sperm seen on TCE was 97.1%. The SRR for 8 men who underwent mTESE after no sperm was found on TCE was 75%. The positive predictive value of TCE for successful TESE result is 94.4% for men with NOA. Treatment success rate of TCE and cTESE was 79.1% with a cost reduction of 59.4%.

CONCLUSION

TCE is a prognostic tool to guide decision making between cTESE and mTESE and maximize sperm retrieval rate while mitigating financial burden and operative complexity. TCE is important to identify ideal candidates for both procedures to maximize efficacy and safety amongst men with NOA.

Heat Shock Transcription Factor 2 Is Significantly Involved in Neurodegenerative Diseases, Inflammatory Bowel Disease, Cancer, Male Infertility, and Fetal Alcohol Spectrum Disorder: The Novel Mechanisms of Several Severe Diseases

HSF (heat shock transcription factor or heat shock factor) was discovered as a transcription factor indispensable for heat shock response. Although four classical HSFs were discovered in mammals and two major HSFs, HSF1 and HSF2, were cloned in the same year of 1991, only HSF1 was intensively studied because HSF1 can give rise to heat shock response through the induction of various HSPs' expression. On the other hand, HSF2 was not well studied for some time, which was probably due to an underestimate of HSF2 itself. Since the beginning of the 21st century, HSF2 research has progressed and many biologically significant functions of HSF2 have been revealed. For example, the roles of HSF2 in nervous system protection, inflammation, maintenance of mitosis and meiosis, and cancer cell survival and death have been gradually unveiled. However, we feel that the fact HSF2 has a relationship with various factors is not yet widely recognized; therefore, the biological significance of HSF2 has been underestimated. We strongly hope to widely communicate the significance of HSF2 to researchers and readers in broad research fields through this review. In addition, we also hope that many readers will have great interest in the molecular mechanism in which HSF2 acts as an active transcription factor and gene bookmarking mechanism of HSF2 during cell cycle progression, as is summarized in this review.

Is testicular microdissection the only way to retrieve sperm for non-obstructive azoospermic men?

Men presenting with non-obstructive azoospermia are the most challenging clinical scenario for an infertile couple. Intracytoplasmic Sperm Injection (ICSI) with testicular sperm retrieval gave a chance for biological fatherhood once sperm can be found, but unfortunately sperm recovery rate (SSR) is something near 50%, leading to a discussion about what surgical retrieval technique is the best. Historically sperm have been retrieved using conventional Testicular Sperm Extraction (c-TESE), Testicular Sperm Aspiration (TESA), a combination of Testicular Fine Needle Aspiration (TfNA)/c-TESE, Testicular Microdissection (TM) and Open Testicular Mapping (OTEM). c-TESE published in 1995 by Devroey and cols. consists of testis delivery, a large unique albuginea incision and extraction of a portion from the majority of testicular tubules. TESA published in 1996 by Lewin and cols. is done percutaneously using a 21–23 gauge needle and a syringe to aspire testicular tubules. TfNA was published in 1965 by Obrant and Persson as an aspiration biopsy and cytological exam to verify sperm production. In 1999 Turek and cols. published the use of TfNA combined with c-TESE for sperm retrieval. In 1999, Peter Schlegel published a technique using a microsurgical approach to identify more probable sperm production areas inside the testicle that could be excised with better precision and less tissue. OTEM is a multiple biopsy approach, published in 2020 by Vieira and cols., based on TfNA principles but done at the same time without albuginea opening or surgical microscope need. Since Testicular Microdissection publication, the method became the gold standard for sperm retrieval, allowing superior SSR with minimal tissue removal, but the amount of testicular dissection to find more probable spermatogenesis areas, difficulties in comparative design studies, diversity TM results among doctors and other methods that can achieve very similar results we question TM superiority. The objective is review existing literature and discuss advantages and disadvantages of all the methods for sperm retrieval in non-obstructive azoospermia.

Investigation of sub-chromosomal changes in males with idiopathic azoospermia by chromosomal microarray analysis

Azoospermia consists of a significant proportion of infertility aetiology in males. Although known genetic abnormalities may explain roughly the third of infertility cases, the exact aetiology is still unclear. Chromosomal microarrays are widely used to detect sub chromosomal abnormalities (e.g., microdeletions and microduplications). This study aimed to investigate aetiology in patients with idiopathic azoospermia by using the chromosomal microarray method to detect possible sub chromosomal changes. Twenty-eight patients (with a mean age of 30.4 ± 9 years) that had been diagnosed with idiopathic azoospermia between January 2019 and December 2020 were included in the study. Genomic DNA isolated from the blood of patients were amplified using polymerase chain reaction and was subjected to chromosomal microarray analysis. A total of six microdeletions were identified as clinically significant: one pathogenic copy number variation (CNV), four likely pathogenic CNVs, and one CNV of unknown clinical significance. However, clinical findings indicated that these microdeletions, with variable expression levels, may affect the spermatogenesis process and induce azoospermia. Future investigations regarding the functional effect of these deletions may contribute to our understanding of azoospermia aetiology.

The Fate of Leydig Cells in Men with Spermatogenic Failure

The steroidogenic cells in the testicle, Leydig cells, located in the interstitial compartment, play a vital role in male reproductive tract development, maintenance of proper spermatogenesis, and overall male reproductive function. Therefore, their dysfunction can lead to all sorts of testicular pathologies. Spermatogenesis failure, manifested as azoospermia, is often associated with defective Leydig cell activity. Spermatogenic failure is the most severe form of male infertility, caused by disorders of the testicular parenchyma or testicular hormone imbalance. This review covers current progress in knowledge on Leydig cells origin, structure, and function, and focuses on recent advances in understanding how Leydig cells contribute to the impairment of spermatogenesis.

OUP accepted manuscript

BACKGROUND

The beneficial effects of hormonal therapy in stimulating spermatogenesis in patients with non-obstructive azoospermia (NOA) and either normal gonadotrophins or hypergonadotropic hypogonadism prior to surgical sperm retrieval (SSR) is controversial. Although the European Association of Urology guidelines state that hormone stimulation is not recommended in routine clinical practice, a significant number of patients undergo empiric therapy prior to SSR. The success rate for SSR from microdissection testicular sperm extraction is only 40–60%, thus hormonal therapy could prove to be an effective adjunctive therapy to increase SSR rates.

OBJECTIVE AND RATIONALE

The primary aim of this systematic review and meta-analysis was to compare the SSR rates in men with NOA (excluding those with hypogonadotropic hypogonadism) receiving hormone therapy compared to placebo or no treatment. The secondary objective was to compare the effects of hormonal therapy in normogonadotropic and hypergonadotropic NOA men.

SEARCH METHODS

A literature search was performed using the Medline, Embase, Web of Science and Clinicaltrials.gov databases from 01 January 1946 to 17 September 2020. We included all studies where hormone status was confirmed. We excluded non-English language and animal studies. Heterogeneity was calculated using I² statistics and risk of bias was assessed using Cochrane tools. We performed a meta-analysis on all the eligible controlled trials to determine whether hormone stimulation (irrespective of class) improved SSR rates and also whether this was affected by baseline hormone status (hypergonadotropic versus normogonadotropic NOA men). Sensitivity analyses were performed when indicated.

OUTCOMES

A total of 3846 studies were screened and 22 studies were included with 1706 participants. A higher SSR rate in subjects pre-treated with hormonal therapy was observed (odds ratio (OR) 1.96, 95% CI: 1.08–3.56, P = 0.03) and this trend persisted when excluding a study containing only men with Klinefelter syndrome (OR 1.90, 95% CI: 1.03–3.51, P = 0.04). However, the subgroup analysis of baseline hormone status demonstrated a significant improvement only in normogonadotropic men (OR 2.13, 95% CI: 1.10–4.14, P = 0.02) and not in hypergonadotropic patients (OR 1.73, 95% CI: 0.44–6.77, P = 0.43). The literature was at moderate or severe risk of bias.

WIDER IMPLICATIONS

This meta-analysis demonstrates that hormone therapy is not associated with improved SSR rates in hypergonadotropic hypogonadism. While hormone therapy improved SSR rates in eugonadal men with NOA, the quality of evidence was low with a moderate to high risk of bias. Therefore, hormone therapy should not be routinely used in men with NOA prior to SSR and large scale, prospective randomized controlled trials are needed to validate the meta-analysis findings.

Boosting effect of testosterone on GDNF expression in Sertoli cell line (TM4); comparison between TM3 cells-produced and exogenous testosterone

The Glial cell-derived neurotrophic factor (Gdnf) and testosterone induce the spermatogonial stem cells (SSCs) self-renewal and spermatogenesis, respectively. In present study the stimulating role of testosterone on Sertoli cells to produce Gdnf, and the possible effect of Gdnf on Gfrα1 and c-RET expressions were investigated. The TM4 cells (line Sertoli cells) were co-cultured with [0.1, 0.2 and 0.4 (ng/ml)] of exogenous and TM3 (line Leydig cells)-produced testosterones, and consequently the TM4-produced Gdnf concentration was evaluated. Next, the SSCs were co-cultured with the TM-4 derived media (endogenous Gdnf) and exogenous Gdnf [0.1, 0.2, and 0.4 ng/ml)]. The 0.1 and 0.2 ng/ml endogenous and 3 concentrations of exogenous testosterone up-regulated the Gdnf expression versus non-treated Sertoli cells. The TM4-produced and exogenous Gdnfs, in all concentrations, up-regulated the receptors expression. In conclusion, the testosterone, solely, stimulates the Gdnf synthesis and the Gdnf, individually, amplifies its receptor's expression at mRNA and protein levels.

Non-obstructive idiopathic azoospermia vs azoospermia with antecedents of cryptorchidism: ways and probabilities of becoming parents

Background

Non-obstructive azoospermia (NOA) with history of cryptorchidism and idiopathic NOA are the most common forms of NOA without genetic aetiology. Of all patients with one of these two types of NOA, only a few will have a positive TEsticular Sperm Extraction (TESE). Of those with positive extraction followed by sperm freezing, not all will have a child after TESE-ICSI. What are the ways and probabilities of taking home a baby for patients with NOA and a history of cryptorchidism compared with patients with idiopathic NOA?

Results

Patients with idiopathic NOA or NOA and a history of cryptorchidism who underwent their first TESE were included. The patients were divided into two groups: Group 1 was composed of 125 patients with idiopathic NOA and Group 2 of 55 patients with NOA and a history of surgically treated cryptorchidism. Our results showed that more than half of the NOA patients succeeded in becoming parents. The main way to fulfil their plans for parenthood is to use sperm or embryo donation (72%) for men with idiopathic NOA, whereas the majority of men with NOA and a history of cryptorchidism had a child after TESE-ICSI (58.8%).

Conclusions

In our centre, before considering TESE for a patient with NOA, we explain systematically TESE-ICSI alternatives (sperm donation, embryo donation or adoption). As a result, the couple can consider each solution to become parents.

MiR-181a Promotes Spermatogenesis by Targeting the S6K1 Pathway

Approximately 15% of couples suffer from infertility worldwide, and male factors contribute to about 30% of total sterility cases. However, there is little progress in treatments due to the obscured understanding of underlying mechanisms. Recently microRNAs have emerged as a key player in the process of spermatogenesis. Expression profiling of miR-181a was carried out in murine testes and spermatocyte culture system. In vitro cellular and biochemical assays were used to examine the effect of miR-181a and identify its target S6K1, as well as elucidate the function with chemical inhibitor of S6K1. Human testis samples analysis was employed to validate the findings. miR-181a level was upregulated during mouse spermatogenesis and knockdown of miR-181a attenuated the cell proliferation and G1/S arrest and increased the level of S6K1, which was identified as a downstream target of miR-181a. Overexpression of S6K1 also led to growth arrest of spermatocytes while inhibitor of S6K1 rescued the miR-181a knockdown-mediated cell proliferation defect. In human testis samples of azoospermia patients, low level of miR-181a was correlated with defects in the spermatogenic process. miR-181a is identified as a new regulator and high level of miR-181a contributes to spermatogenesis via targeting S6K1.

Gene Alterations and Expression Spectrum of NANOS3 in Nonobstructive Azoospermia

Nanos3, a zinc finger RNA-binding protein, suppresses the apoptosis in primordial germ cells (PGCs) during migration to gonads and maintains the PGC population. The genetic variations and expression of NANOS3 in patients with non-obstructive azoospermia (NOA) were evaluated in this study. The study included 100 idiopathic infertile men with NOA and 100 fertile men as the as the case and control groups, respectively. NANOS3 gene variations were analyzed using the standard polymerase chain reaction (PCR) and sequencing. For mRNA and protein expression analysis, testicular biopsy specimens from 27 patients including 9 obstructive azoospermia (OA), 9 maturation arrest (MA), and 9 Sertoli cell-only syndromes (SCOS) were collected and evaluated using the real-time PCR technique and immunohistochemistry. Although the evaluation of the 5`UTR regulatory region has shown the significant difference in the numbers of TG repeats in rs11182456 between groups, the odd ratio was not strong enough to consider that as a certain risk factor lead to azoospermia and infertility. Meanwhile, NANOS3 expression at mRNA level had a significant difference among OA, SCOS, and MA groups.

Current updates and future perspectives in the evaluation of azoospermia: A systematic review

Objectives: To provide a summary of the current evaluation of azoospermia and insights into future perspectives in the evaluation and counselling of men with azoospermia. Methods: A search of PubMed, Cochrane Reviews and Web of Science databases was performed for full-text English-language articles published between 1943 and 2020 focussing on 'future perspectives', 'azoospermia' and 'evaluation'. Results: Azoospermia represents a severe form of male infertility characterised by sperm production so impaired that there are no sperm present in the ejaculate. The current evaluation of azoospermia focusses on patient history and physical examination with selected adjunctive laboratory investigations including serum hormones, a karyotype and screening for Y chromosome microdeletions. Future diagnostics are focussed on identifying the underlying genetic aetiologies for azoospermia, as well as a greater emphasis on screening for systemic illness that men with severe infertility may be predisposed to develop. Conclusion: Azoospermia represents an extreme form of male infertility, and evaluation relies heavily on history and physical examination, as genetic evaluations for these individuals remain limited. Future evaluation will focus on next-generation sequencing and more rigorous evaluation for possible co-existing and future risk of systemic disease. ABBREVIATIONS: ADGRG2, adhesion G protein-coupled receptor G2; ASRM: American Society of Reproductive Medicine; AZF: azoospermia factor; CBAVD: congenital bilateral absence of the vas deferens; CFTR: cystic fibrosis transmembrane conductance regulator; CRKL: CRK-like proto-oncogene; E2F1: E2F transcription factor 1; HAUS7: HAUS augmin-like complex subunit 7; HR: hazard ratio; KS: Klinefelter syndrome; MAZ, MYC-associated zinc finger protein; NGS: next-generation sequencing; NOA: non-obstructive azoospermia; OA: obstructive azoospermia; RHOX: reproductive homeobox on the X chromosome; SH2: SRC homology 2; TAF7L: TATA-box binding protein associated factor 7-like; TEX11: testis-expressed 11; WES: whole-exome sequencing.

Two Decades from the Introduction of Microdissection Testicular Sperm Extraction: How This Surgical Technique Has Improved the Management of NOA

The treatment of men with non-obstructive azoospermia (NOA) has improved greatly over the past two decades. This is in part due to the discovery of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), but also significantly due to improvements in surgical sperm retrieval methods, namely the development of microdissection testicular sperm extraction (mTESE). This procedure has revolutionized the field by allowing for identification of favorable seminiferous tubules while simultaneously limiting the amount of testicular tissue removed. Improving sperm retrieval rates is imperative in this cohort of infertile men as there are a limited number of factors that are predictive of successful sperm retrieval. Currently, sperm retrieval in NOA men remains dependent on surgeon experience, preoperative patient optimization and teamwork with laboratory personnel. In this review, we discuss the evolution of surgical sperm retrieval methods, review predictors of sperm retrieval success, compare and contrast the data of conventional versus mTESE, share tips for optimizing sperm retrieval outcomes, and discuss the future of sperm retrieval in men with NOA.

Spermatogonial Stem Cell Numbers Are Reduced by Transient Inhibition of GDNF Signaling but Restored by Self-Renewing Replication when Signaling Resumes

One cause of human male infertility is a scarcity of spermatogonial stem cells (SSCs) in testes with Sertoli cells that neither produce adequate amounts of GDNF nor form the Sertoli-Sertoli junctions that form the blood-testis barrier (BTB). These patients raise the issue of whether a pool of SSCs, depleted due to inadequate GDNF stimulation, will expand if normal signaling is restored. Here, we reduce adult mouse SSC numbers by 90% using a chemical-genetic approach that reversibly inhibits GDNF signaling. Signal resumption causes all remaining SSCs to replicate immediately, but they primarily form differentiating progenitor spermatogonia. Subsequently, self-renewing replication restores SSC numbers. Testicular GDNF levels are not increased during restoration. However, SSC replication decreases as numbers of SSCs and progenitors increase, suggesting important regulatory interactions among these cells. Finally, sequential loss of SSCs and then pachytene spermatocytes causes dissolution of the BTB, thereby recapitulating another important characteristic of some infertile men.

Insights and clinical potential of proteomics in understanding spermatogenesis

Introduction: With the worldwide decline on male fertility potential, the importance of the insight of the spermatogenic process has been increasing. In recent years, proteomic methodologies have been applied to seminal fluid of infertile men to search for infertility potential biomarkers. However, to understand the spermatogenic event and to search for treatment to spermatogenic impairment, comparative analysis of testicular proteomics is considered a powerful methodology.Areas covered: Herein, we present a critical overview of the studies addressing proteomic alterations in the development of spermatogenesis during puberty, as well as during the different phases of the spermatogenic event. The comparative studies of the proteomic testicular profile of men with and without spermatogenic impairment are also discussed and key proteins and pathways involved highlighted.Expert opinion: The usage of whole human testicular tissue with its heterogeneous cellular composition makes proteome data interpretation particularly challenging. This may be minimized by controlled experiments involving the collection of testicular tissue and sperm from the same individuals, integrated in a clinically characterized cohort of healthy and infertile men. The analysis of specific subcellular proteomes can add more information to the proteomic puzzle, opening new treatment possibilities for infertile/subfertile men.

Sperm retrieval by conventional testicular sperm extraction for assisted reproduction in patients with Zinner syndrome

We present data from three Caucasian men with Zinner syndrome who attended our center for the treatment of primary couple’s infertility. Each patient was scheduled for conventional testicular sperm extraction (cTESE) and cryopreservation. Sperm analysis confirmed absolute azoospermia. Patient 1 had right and left testis volumes of 24 mL and 23 mL, respectively; left seminal vesicle (SV) agenesis, severe right SV hypotrophy with right renal agenesis. Follicle-stimulating hormone (FSH) was 3.2 IU/L. Patient 2 exhibited right and left testis volumes of 18 mL and 16 mL, respectively; a left SV cyst of 32 × 28 mm, ipsilateral kidney absence, and right SV agenesis. FSH was 2.8 IU/L. Patient 3 showed a testicular volume of 10 mL bilaterally, a 65 × 46 mm left SV cyst, right SV enlargement, and left kidney agenesis. FSH was 32.0 IU/L. Sperm retrieval was successful in all patients. Nevertheless, cTESE should be performed on the day of oocyte retrieval.

Male Infertility in Humans: An Update on Non-obstructive Azoospermia (NOA) and Obstructive Azoospermia (OA)

Non-obstructive azoospermia (NOA) and obstructive azoospermia (OA) are two common causes of infertility that affect a considerable number of men. However, few studies were performed to understand the molecular etiology of these disorders. Studies based on bioinformatics and genetic analyses in recent years, however, have yielded insightful information and have identified a number of genes that are involved in these disorders. In this review, we briefly summarize and evaluate these findings. We also discuss findings based on epigenetic modifications of sperm DNAs that affect a number of genes pertinent to NOA and OA. The information summarized in this Chapter should be helpful to investigators in future functional studies of NOA and OA.

Infertility case presentation in Zinner syndrome: Can a long-lasting seminal tract obstruction cause secretory testicular injury?

Zinner syndrome (ZS) could represent an uncommon cause of male infertility, as result of the ejaculatory duct block, which typically leads to low seminal volume and azoospermia. A 27-year-old Caucasian man reported persistent events of scrotal-perineal pain and dysuria during the past 6 months. The andrological examination showed testicular volume of 10 ml bilaterally. Follicle-stimulating hormone was 32.0 IU/L, luteinising hormone was 16.3 IU/L, total testosterone was 9.0 nmol/L, and 17-beta-oestradiol was 0.12 nmol/L. The semen analysis revealed absolute azoospermia, semen volume of 0.6 ml and semen pH of 7.6. The abdominal contrast-enhanced computed tomography showed (a) left kidney agenesis; (b) an ovaliform hypodense mass of 65 × 46 millimetres with fluid content, which was shaping the bladder and the left paramedian prostatic region, compatible with a left seminal vesicle pseudocyst; and (c) an enlargement of the right seminal vesicle. The patient was diagnosed with ZS, and he was scheduled for robot-assisted laparoscopic left vesiculectomy. Subsequently, testis biopsy was characterised by complete germ cell aplasia. The onset symptomatology is often blurred and difficult to detect. It is important to diagnose and manage early this condition, because a long-lasting seminal tract obstruction could determine an irreversible secretory testicular injury.

Aberrant gene expression by Sertoli cells in infertile men with Sertoli cell-only syndrome

Sertoli cell-only (SCO) syndrome is a severe form of human male infertility seemingly characterized by the lack all spermatogenic cells. However, tubules of some SCO testes contain small patches of active spermatogenesis and thus spermatogonial stem cells. We hypothesized that these stem cells cannot replicate and seed spermatogenesis in barren areas of tubule because as-of-yet unrecognized deficits in Sertoli cell gene expression disable most stem cell niches. Performing the first thorough comparison of the transcriptomes of human testes exhibiting complete spermatogenesis with the transcriptomes of testes with SCO syndrome, we defined transcripts that are both predominantly expressed by Sertoli cells and expressed at aberrant levels in SCO testes. Some of these transcripts encode proteins required for the proper assembly of adherent and gap junctions at sites of contact with other cells, including spermatogonial stem cells (SSCs). Other transcripts encode GDNF, FGF8 and BMP4, known regulators of mouse SSCs. Thus, most SCO Sertoli cells can neither organize junctions at normal sites of cell-cell contact nor stimulate SSCs with adequate levels of growth factors. We propose that the critical deficits in Sertoli cell gene expression we have identified contribute to the inability of spermatogonial stem cells within small patches of spermatogenesis in some SCO testes to seed spermatogenesis to adjacent areas of tubule that are barren of spermatogenesis. Furthermore, we predict that one or more of these deficits in gene expression are primary causes of human SCO syndrome.

Ninety babies born after round spermatid injection into oocytes: survey of their development from fertilization to 2 years of age

OBJECTIVE

To compare physical and cognitive development of babies born after round spermatid injection (ROSI) with those born after natural conception.

DESIGN

Comparison of efficiencies of ROSI and ICSI using testicular spermatozoa, performed in the St. Mother Clinic. Physical and cognitive development of ROSI babies recorded by parents in the government-issued Mother-Child Handbook was checked and verified by attending pediatricians. Data included baby's weight gain and response to parents' voice/gesture.

SETTING

Assisted reproduction technology practice.

PATIENT(S)

A total of 721 men participated in ROSI; 90 ROSI babies were followed for 2 years for their physical and cognitive development. Control subjects were 1,818 naturally born babies.

INTERVENTION(S)

Surgical retrieval of spermatogenic cells from testes; selection and injection of round spermatids into oocytes; oocyte activation, in vitro culture of fertilized eggs, and embryo transfer to mothers.

MAIN OUTCOME MEASURE(S)

Physical and cognitive development of ROSI babies (e.g., body weight increase, response to parents, and understanding and speaking simple language) compared with naturally born babies.

RESULT(S)

Of 90 ROSI babies, three had congenital aberrations at birth, which corrected spontaneously (ventricular septa) or after surgery (cleft lip and omphalocele). Physical and cognitive development of ROSI babies was similar to those of naturally born babies.

CONCLUSION(S)

There were no significant differences between ROSI and naturally conceived babies in either physical or cognitive development during the first 2 years after birth.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN Clinical Trials Registry UMIN000006117.

Cryostorage of testicular tissue and retransplantation of spermatogonial stem cells in the infertile male

Transplantation of own cryostored spermatogonial stem cells (SSCs) is a promising technique for fertility restoration when the SSC pool has been depleted. In this regard, cryopreservation of pre-pubertal testicular tissue or SSCs suspensions before gonadotoxic therapies is ethically accepted and increasingly proposed. SSC transplantation has also been considered to treat other causes of infertility relying on the possibility of propagating SSCs retrieved in the testes of infertile men before autologous re-transplantation. Although encouraging results were achieved in animals and in preclinical experiments, clinical perspectives are still limited by a number of unresolved technical and safety issues, such as the risk of cancer cell contamination of cells intended for transplantation and the genetic and epigenetic stability of SCCs when cultured before re-transplantation. Moreover, while genome editing techniques raise the hope of modifying the SSCs genome before re-transplantation, their application for reproductive purposes might be a step too far for the moment.

Novel method of histopathological analysis after testicular sperm extraction in patients with nonobstructive and obstructive azoospermia

Objective

To assess whether the “testicular pool” could be used for histological analysis and whether it gave more accurate information than the standard testicular biopsy.

Methods

Between January 2017 and March 2018, this single-center prospective study included 60 azoospermic men undergoing conventional bilateral testicular sperm extraction. Six samples were excised from each testicle and transferred to an embryologist. One additional biopsy was randomly taken from each testis for a histological analysis. After processing, the testicular pool was also sent for a histological analysis, which showed normal spermatogenesis (NS), hypospermatogenesis (HYPO), maturation arrest (MA), Sertoli cell-only syndrome (SCOS), and tubular atrophy (TA).

Results

Twenty of the 60 patients (33.3%) had obstructive azoospermia (OA), while the remaining 40 (66.6%) had nonobstructive azoospermia. Their mean age was 40.5 years. All patients with OA had previously undergone unsuccessful testicular fine-needle aspiration. Successful sperm retrieval (SSR) occurred in 93.3% of patients. Histological analysis of the testicular biopsy revealed NS in 12 patients (20%), HYPO and TA in 28 patients (46.6%), MA in eight patients (13.3%), and SCOS in 12 patients (20%). The testicular pool analysis showed NS in 12 patients (20%), HYPO and TA in 44 patients (73.3%), MA in four patients (6.6%), and SCOS in no patients. In four patients with MA (6.6% of the total sample) and 12 patients with SCOS (20% of the total sample) according to the standard testicular biopsy, the embryologist found SSR with cryopreservation. Overall, in 44 patients (73.3%), the testicular pool analysis confirmed the histological findings of the standard testicular biopsy. In the 16 cases (26.6%) with a discrepancy between the single-biopsy histological findings and SSR, the testicular pool analysis confirmed the embryological data on SSR.

Conclusion

The testicular pool proved to be easily analyzable, practical, manageable, and more accurate for predicting sperm retrieval than standard testicular biopsy.

Relevance of testicular histopathology on prediction of sperm retrieval rates in case of non-obstructive and obstructive azoospermia

Introduction:

The aim of our research was to establish the relevance of testicular histopathology on sperm retrieval after testicular sperm extraction in patients with non-obstructive azoospermia and in patients with obstructive azoospermia, who already underwent a previous failure testicular fine needle aspiration.

Methods:

We evaluated a total of 82 azoospermic men, underwent testicular sperm extraction, referring to the Assisted Reproductive Technology Centre of the University of Florence, Italy between January 2008 and March 2017. A general and genital physical examination, scrotal and trans-rectal ultrasound, semen analysis, hormone measurements, including follicle-stimulating hormone, luteinizing hormone and total testosterone, were collected.

Results:

Successful sperm retrieval was obtained in 36 men of total (43.9%). Successful sperm retrieval was 29.5% in non-obstructive azoospermia patients, while men with obstructive azoospermia, who, underwent a previous failure testicular fine needle aspiration, had sperm retrieval in 86% of cases. Mean luteinizing hormone was 6.55 IU/L, total testosterone 4.70 ng/mL, right testicular volume 13.7 mL and left testicular volume 13.6 mL. Mean Follicle-stimulating hormone was 13.45 IU/L in patients with negative sperm retrieval and 8.18 IU/L in men with successful sperm retrieval. According to histology, 20.7% had normal spermatogenesis, 35.3% hypospermatogenesis, 35.3% maturation arrest and 8.5% Sertoli cell-only syndrome. Successful sperm retrieval was 88.2% in patients with normal spermatogenesis, 24.1% in the maturation arrest group and 48.27% in patients with hypospermatogenesis, while negative sperm retrieval was reported in Sertoli cell-only syndrome patients. Seven cases with maturation arrest showed a successful sperm retrieval.

Conclusion:

Testicular histopathology after testicular sperm extraction offers important information on prediction of sperm retrieval and can guide the surgeon in choosing the more suitable therapeutic practice.

Prediction of male infertility by the World Health Organization laboratory manual for assessment of semen analysis: A systematic review

Objective

To discuss the role, reliability and limitations of the semen analysis in the evaluation of fertility with reference to the World Health Organization (WHO) fifth edition guidelines, with semen analysis reference values published in 2010. We also discuss the limitations of using a single threshold value to distinguish ‘abnormal’ and ‘normal’ parameters.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to search the MEDLINE, EMBASE, and the Cochrane electronic database for articles discussing the effectiveness of semen analysis.

Results

Limitations affecting the reliability of semen analysis as a predictor of fertility were found. These include: the lack of consideration of the female factor, the vaguely defined threshold values, and the intra-individual variation in semen parameters.

Conclusions

Impaired semen parameters alone cannot be used to predict fertility as these men still have a chance of being fertile, except when a man has azoospermia, necrospermia or globozoospermia.

Differential Diagnostic Value of Obstructive and Nonobstructive Azoospermia by Scrotal Ultrasound

Our objective was to assess the differential diagnostic value of classification of obstructive versus nonobstructive azoospermia by scrotal ultrasound. Forty patients with azoospermia were selected for our study (ages, 23-35; average, 29 ± 5.34 years). Patients were divided into the obstructive (17) or nonobstructive (23) azoospermia category. Twenty "healthy" volunteers were selected for the control group. We observed the testis, epididymis, and vas deferens in all subjects. Testicular volumes were calculated and compared with the control group for both obstructive and nonobstructive groups. Cystic or tubular dilation of the epididymis was found in all patients with obstructive azoospermia. The patients with nonobstructive azoospermia had no significant abnormalities of the epididymis. There was no difference in the testicular volumes between the patients with obstructive azoospermia and healthy controls (P > 0.05). However, the testicular volumes of patients with nonobstructive azoospermia were smaller than those of healthy volunteers (P < 0.05). It is helpful to identify obstructive and nonobstructive azoospermia by scrotal ultrasound, because it is a less invasive method that can be used to isolate probable treatment options.

The production of glial cell line-derived neurotrophic factor by human sertoli cells is substantially reduced in sertoli cell-only testes

STUDY QUESTION

Do human Sertoli cells in testes that exhibit the Sertoli cell-only (SCO) phenotype produce substantially less glial cell line-derived neurotrophic factor (GDNF) than Sertoli cells in normal testes?

SUMMARY ANSWER

In human SCO testes, both the amounts of GDNF mRNA per testis and the concentration of GDNF protein per Sertoli cell are markedly reduced as compared to normal testes.

WHAT IS KNOWN ALREADY

In vivo, GDNF is required to sustain the numbers and function of mouse spermatogonial stem cells (SSCs) and their immediate progeny, transit-amplifying progenitor spermatogonia. GDNF is expressed in the human testis, and the ligand-binding domain of the GDNF receptor, GFRA1, has been detected on human SSCs. The numbers and/or function of these stem cells are markedly reduced in some infertile men, resulting in the SCO histological phenotype.

STUDY DESIGN, SIZE, AND DURATION

We determined the numbers of human spermatogonia per mm2 of seminiferous tubule surface that express GFRA1 and/or UCHL1, another marker of human SSCs. We measured GFRA1 mRNA expression in order to document the reduced numbers and/or function of SSCs in SCO testes. We quantified GDNF mRNA in testes of humans and mice, a species with GDNF-dependent SSCs. We also compared GDNF mRNA expression in human testes with normal spermatogenesis to that in testes exhibiting the SCO phenotype. As controls, we also measured transcripts encoding two other Sertoli cell products, kit ligand (KITL) and clusterin (CLU). Finally, we compared the amounts of GDNF per Sertoli cell in normal and SCO testes.

PARTICIPANTS/MATERIALS SETTING METHODS

Normal human testes were obtained from beating heart organ donors. Biopsies of testes from men who were infertile due to maturation arrest or the SCO phenotype were obtained as part of standard care during micro-testicular surgical sperm extraction. Cells expressing GFRA1, UCHL1 or both on whole mounts of normal human seminiferous tubules were identified by immunohistochemistry and confocal microscopy and their numbers were determined by image analysis. Human GDNF mRNA and GFRA1 mRNA were quantified by use of digital PCR and Taqman primers. Transcripts encoding mouse GDNF and human KITL, CLU and 18 S rRNA, used for normalization of data, were quantified by use of real-time PCR and Taqman primers. Finally, we used two independent methods, flow cytometric analysis of single cells and ELISA assays of homogenates of whole testis biopsies, to compare amounts of GDNF per Sertoli cell in normal and SCO testes.

MAIN RESULTS AND THE ROLE OF CHANCE

Normal human testes contain a large population of SSCs that express GFRA1, the ligand-binding domain of the GDNF receptor. In human SCO testes, GFRA1 mRNA was detected but at markedly reduced levels. Expression of GDNF mRNA and the amount of GDNF protein per Sertoli cell were also significantly reduced in SCO testes. These results were observed in multiple, independent samples, and the reduced amount of GDNF in Sertoli cells of SCO testes was demonstrated using two different analytical approaches.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

There currently are no approved protocols for the in vivo manipulation of human testis GDNF concentrations. Thus, while our data suggest that insufficient GDNF may be the proximal cause of some cases of human male infertility, our results are correlative in nature.

WIDER IMPLICATIONS OF THE FINDINGS

We propose that insufficient GDNF expression may contribute to the infertility of some men with an SCO testicular phenotype. If their testes contain some SSCs, an approach that increases their testicular GDNF concentrations might expand stem cell numbers and possibly sperm production.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Centers for Translational Research in Reproduction and Infertility Program (NCTRI) Grant 1R01HD074542-04, as well as grants R01 HD076412-02 and P01 HD075795-02 and the U.S.-Israel Binational Science Foundation. Support for this research was also provided by NIH P50 HD076210, the Robert Dow Foundation, the Frederick & Theresa Dow Wallace Fund of the New York Community Trust and the Brady Urological Foundation. There are no competing interests.

Management of non-obstructive azoospermia

Non-obstructive azoospermia (NOA) is defined as no sperm in the ejaculate due to failure of spermatogenesis and is the most severe form of male infertility. The etiology of NOA is either intrinsic testicular impairment or inadequate gonadotropin production. Chromosomal or genetic abnormalities should be evaluated because there is a relatively high incidence compared with the normal population. Although rare, NOA due to inadequate gonadotropin production is a condition in which fertility can be improved by medical treatment. In contrast, there is no treatment that can restore spermatogenesis in the majority of NOA patients. Consequently, testicular extraction of sperm under an operating microscope (micro-TESE) has been the first-line treatment for these patients. Other treatment options include varicocelectomy for NOA patients with a palpable varicocele and orchidopexy if undescended testes are diagnosed after adulthood, although management of these patients remains controversial. Advances in retrieving spermatozoa more efficiently by micro-TESE have been made during the past decade. In addition, recent advances in biotechnology have raised the possibility of using germ cells produced from stem cells in the future. This review presents current knowledge about the etiology, diagnosis, and treatment of NOA.

Predictive factors for natural pregnancy after microsurgical reconstruction in patients with primary epididymal obstructive azoospermia

Primary epididymal obstructive azoospermia (OA) is the most prevalent form of OA in nonvasectomized patients and has been less studied. We aim to assess the results with microsurgical vasoepididymostomy used in the treatment of men diagnosed with primary epididymal obstructive azoospermia and to identify the factors associated with natural pregnancy occurring after microsurgical reconstruction. This prospective study included consecutive patients with epididymal OA who underwent microsurgical reconstruction in our center. Clinical and biological data were obtained every three months during follow-up. Occurrence of natural pregnancy was the primary study outcome. In total, 36 patients underwent microsurgical reconstruction. The mean age was 34 ± 4.5 years (range 24-46 years). Median follow-up time was 15 [IQR 12-21] months. The total patency rate was 77.7% (n = 28). During follow-up, 8 (22.2%) natural pregnancies occurred. The overall live birth rate was 100%. Low FSH levels (HR: 0.22; 95% CI: 0.052-0.88; P = 0.032) and higher total motile sperm count (TMSC) (HR: 1.001; 95% CI 1-1.001; P = 0.012) were associated with a higher rate of natural pregnancy. Our data suggest that microsurgical vasoepididymostomy is an effective therapy of primary epididymal OA. Baseline lower FSH and higher TMSC were independent predictors for natural pregnancy occurrence.

rs189037, a functional variant in ATM gene promoter, is associated with idiopathic nonobstructive azoospermia

OBJECTIVE

To investigate the relationship between a functional variant rs189037(G>A) in ATM promoter and idiopathic nonobstructive azoospermia (INOA) in a Chinese population.

DESIGN

Case-control study.

SETTING

Medical academy and hospital.

PATIENT(S)

Two hundred twenty-nine INOA patients and 236 fertile male controls.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Genotyping was performed by polymerase chain reaction-based restriction fragment length polymorphism and subsequently confirmed by DNA sequencing. Odds ratio (ORs) and 95% confidence intervals (95% CIs) were calculated for the risk genotype and allele. Bioinformatic analysis was also performed to predict the biological function of rs189037(G>A).

RESULT(S)

The AA genotype and A allele at rs189037(G>A) locus were both associated with an increased risk of INOA, with OR 1.90 (95% CI 1.214-3.007) for AA and 1.41 (95% CI 1.112-1.775) for A allele. The heterozygous GA and GA+AA had no relationship with INOA risk, with OR 1.06 (95% CI 0.761-1.472) and 1.28 (95% CI 0.954-1.708), respectively. Meanwhile, stratification by genotype showed that INOA patients with AA had higher FSH level, lower total T level, and smaller testicular size than those patients with GG. Furthermore, bioinformatic analysis predicted that the rs189037(G>A) variant was located in a well-conserved region in ATM promoter and that the transition of allele G to allele A might lead to differential allelic expression of ATM gene via modifying of the DNA-binding ability of transcription factor E2F1.

CONCLUSION(S)

The genetic variant rs189037(G>A) in ATM gene promoter contributes to an increased risk of INOA in a Chinese population, possibly through affecting the DNA-binding ability of E2F1 and subsequent ATM expression.

The epidemiology and etiology of azoospermia

The misconception that infertility is typically associated with the female is commonly faced in the management of infertile men. It is uncommon for a patient to present for an infertility evaluation with an abnormal semen analysis report before an extensive female partner workup has been performed. Additionally, a man is usually considered fertile based only on seminal parameters without a physical exam. This behavior may lead to a delay in both the exact diagnosis and in possible specific infertility treatment. Moreover, male factor infertility can result from an underlying medical condition that is often treatable but could possibly be life-threatening. The responsibility of male factor in couple's infertility has been exponentially rising in recent years due to a comprehensive evaluation of reproductive male function and improved diagnostic tools. Despite this improvement in diagnosis, azoospermia is always the most challenging topic associated with infertility treatment. Several conditions that interfere with spermatogenesis and reduce sperm production and quality can lead to azoospermia. Azoospermia may also occur because of a reproductive tract obstruction. Optimal management of patients with azoospermia requires a full understanding of the disease etiology. This review will discuss in detail the epidemiology and etiology of azoospermia. A thorough literature survey was performed using the Medline, EMBASE, BIOSIS, and Cochrane databases. We restricted the survey to clinical publications that were relevant to male infertility and azoospermia. Many of the recommendations included are not based on controlled studies.

An update on sperm retrieval techniques for azoospermic males

The use of non-ejaculated sperm coupled with intracytoplasmic sperm injection has become a globally established procedure for couples with azoospermic male partners who wish to have biological offspring. Surgical methods have been developed to retrieve spermatozoa from the epididymides and the testes of such patients. This article reviews the methods currently available for sperm acquisition in azoospermia, with a particular focus on the perioperative, anesthetic and technical aspects of these procedures. A critical analysis of the advantages and disadvantages of these sperm retrieval methods is provided, including the authors' methods of choice and anesthesia preferences.

Predictive factors for sperm retrieval and sperm injection outcomes in obstructive azoospermia: do etiology, retrieval techniques and gamete source play a role?

Obstructive azoospermia is a relatively common male infertility condition. The main etiologies of obstructive azoospermia include congenital, surgical-derived, traumatic and post-infectious cases. Although seminal tract reconstruction is a cost-effective treatment in most cases, this approach may not be feasible or desired in some cases. In such cases, assisted reproduction techniques offer a method for achieving pregnancy, notably via sperm retrieval and intracytoplasmic sperm injection. This process requires several considerations and decisions to be made, including the cause and duration of obstruction, which sperm retrieval technique to use, and whether to use fresh or frozen-thawed sperm. We present a review of obstructive azoospermia and assisted reproduction techniques, highlighting the most relevant aspects of the decision-making process for use in clinical practice.

Pregnancy after percutaneous epididymal sperm aspiration in an 81-year-old man with obstructive azoospermia

There has been observed a trend to delay childbearing, reflecting couple's desire to have children at older ages. Maternal age is a well-known factor that influences the achievement of a pregnancy. In contrast, there are few studies examining the effect of paternal age on the outcomes of assisted reproductive technologies (ART), and results are conflicting. Our patient was vasectomised at the age of 60 years, and his wife was 38 years old. A total of four metaphase II oocytes were inseminated 4 h later (day 0) by intracytoplasmic sperm injection using spermatozoa from percutaneous epididymal sperm aspiration. On day 2, the three resulting embryos were transferred (two had four cells, and one had two cells). Two healthy infants were born at the 37th gestational week by caesarean section. Although the effect of paternal age on ART outcomes and results are conflicting, this case report contributes to point out that advanced age of the man has probably lesser negative influence in the reproductive function.

Surgical techniques for the management of male infertility

Evaluation and surgical treatment of male infertility has evolved and expanded, now leading to more precise diagnoses and tailored treatments with diminished morbidity and greater success. Surgeries for male infertility are divided into four major categories: (i) diagnostic surgery; (ii) surgery to improve sperm production; (iii) surgery to improve sperm delivery; and (iv) surgery to retrieve sperm for use with in vitro fertilization and intracytoplasmic sperm injection (IVF-ICSI). While today we are more successful than ever in treating male infertility, pregnancy is still not always achieved likely due to factors that remain poorly understood. Clinicians treating infertility should advocate for couple-based therapy, and require that both partners have a thorough evaluation and an informed discussion before undergoing specific surgical therapies.

Surgical treatment of male infertility in the era of intracytoplasmic sperm injection - new insights

Assisted reproductive technology is an evolving area, and several adjuvant procedures have been created to increase a couple's chance of conceiving. For male infertility, the current challenges are to properly accommodate old and new techniques that are both cost-effective and evidence-based. In this context, urologists are expected to diagnose, counsel, provide medical or surgical treatment whenever possible and/or correctly refer male patients for assisted conception. Urologists are sometimes part of a multiprofessional team in an assisted reproduction unit and are responsible for the above-cited tasks as well as the surgical retrieval of sperm from either the epididymides or testicles. We present a comprehensive review of the surgical treatment options for infertile males, including the perioperative planning and prognostic aspects, with an emphasis on the role of microsurgery in the optimization of treatment results. This review also discusses current techniques for sperm retrieval that are used in association with assisted reproductive technology and includes sperm retrieval success rates according to the technique and the type of azoospermia. New insights are provided with regard to each surgical treatment option in view of the availability of assisted conception to overcome male infertility.

Role of genetics in azoospermia

OBJECTIVE

To review established genetic causes of azoospermia, the most severe form of male infertility, and help clinicians, scientists, and infertile couples considering assisted reproductive technologies (ART) to understand the complexity of the disorder and to maximize the chances of having a healthy infant through proper counseling and treatment.

METHOD

An initial literature search was performed on PubMed using the key words "azoospermia" "oligospermia," and "genetics." The results were limited to the studies on humans and written in English, which were written within last 10 years. Although preliminary query results showed more than 900 articles, further queries using key words, such as "Y chromosome," "monogenics," "aneuploidy," "mitochondrial DNA," and "epigenetics," along with "azoospermia," narrowed the results to 30 papers, which were included in the present study.

RESULTS

Genetic defects causing azoospermia were categorized into two large categories: chromosomal and nonchromosomal. Chromosomal defects were further categorized into (1) structural abnormalities, such as Y chromosome micro/macrodeletions, chromosomal inversions, and translocations; and (2) numerical abnormalities, also known as aneuploidy. Nonchromosomal defects included sperm mitochondrial genome defects and epigenetic alterations of genome.

CONCLUSIONS

As a result of advancements in ART, understanding the potential implications of genetic disorders for infertile couples is critical. Analysis of a potential genetic role in azoospermia holds promise to expand our knowledge to evaluate male infertility and to guide treatments.