Search Results (19)

Non-obstructive azoospermia (NOA) is characterized by focal and quantitatively limited spermatogenesis, making preoperative prediction of sperm retrieval difficult. Seminal plasma is a biologically plausible liquid-biopsy compartment because it contains testicular, epididymal and accessory-gland secretions enriched with extracellular vesicles, cell-free nucleic acids, proteins and metabolites. This narrative molecular review examines the mechanisms by which germ-cell-derived molecular cargo reaches the ejaculate and organizes seminal-plasma biomarkers by cargo class and spermatogenic stage. Particular attention is given to extracellular-vesicle non-coding RNAs, cell-free seminal mRNAs, germ-cell-enriched proteins including TEX101 and ECM1, and metabolomic and lipidomic signatures. Although several markers show promising discrimination, most remain discovery-stage, single-center and insufficiently validated. The central argument is that the field should move from isolated biomarker nomination toward locked, stage-mapped multi-analyte panels integrated with clinical and genetic predictors under modern prediction-model standards. Seminal plasma is best viewed not as a ready clinical test, but as a biologically coherent platform for future calibrated, externally validated and artificial-intelligence (AI)-ready sperm-retrieval decision support. Full article

Background/Objectives: Cryptorchidism is a common cause of male infertility and often results in azoospermia. However, the metabolic perturbations underlying cryptorchidism complicated with azoospermia and their association with surgical sperm retrieval outcomes remain poorly defined. Methods: A total of 35 patients with cryptorchidism and azoospermia, as well as 40 controls with normal semen parameters, were enrolled in the study. Seminal plasma samples from all participants were subjected to metabolomic analysis. Additionally, some patients underwent micro-TESE; the association between metabolomic features and the success or failure of surgical sperm retrieval was further analyzed. Results: A total of 931 differential metabolites were identified between patients and controls, primarily enriched in lipid metabolism and amino acid metabolism pathways. Lipid metabolites were broadly downregulated in patients, while several inflammation-related metabolites, including Prostaglandin E2, were upregulated. Routine clinical parameters showed no significant differences between patients with successful and failed micro-TESE. However, metabolomic profiles effectively distinguished these two subgroups. These differential metabolites between the two subgroups were mainly involved in three key pathways: phenylalanine–tyrosine–tryptophan biosynthesis, aminoacyl-tRNA biosynthesis, and folate biosynthesis. Most metabolites in the first two pathways were downregulated in the successful retrieval group, while those in the folate biosynthesis pathway showed the opposite regulatory trend. Four metabolites, including Leucine, 7,8-Dihydroneopterin, L-Tyrosine and Pterin, exhibited robust predictive value for micro-TESE outcomes. Conclusions: This study reveals distinct metabolic signatures in patients of cryptorchidism with azoospermia. The identified metabolic biomarkers provide valuable references for clinical decision-making regarding micro-TESE, facilitating a personalized assessment of sperm retrieval feasibility. Full article

Parasitic infection is a major cause of infertility in small ruminants. This study aimed to assess the association between bioelectrical impedance analysis (BIA) measurements, testicular morphometrics, and sperm quality in parasitized goats. Thirty-eight intact mature Spanish bucks were allowed to graze on a naturally parasitically infected pasture for 3 months. Nineteen bucks were dewormed regularly (healthy group), while the other 19 bucks did not receive any anthelmintics (parasitized group). Fecal and blood samples were collected weekly to assess fecal egg count (FEC) and packed cell volume (PCV), respectively. Based on the size and morphology of the parasite eggs, they were presumptively identified as Haemonchus contortus. At the end of the grazing period, bucks were slaughtered, and testicles and epididymis were collected for analysis. In addition, BIA was applied to each testicle to measure series resistance (Rs) and reactance (Xc). Epididymal spermatozoa were retrieved and evaluated for motility, viability, morphology, and membrane and acrosome integrities. Data was analyzed using the Mann–Whitney U and Pearson Correlation Coefficient tests. The results showed that Rs (169.41 ± 1.76 Ω vs. 235.21 ± 20.21 Ω), Xc (37.55 ± 0.48 Ω vs. 52.08 ± 4.68 Ω), testicular and epididymis weights and lengths, sperm motility, viability, and membrane and acrosome integrities were lower (p < 0.0001) in parasitized than in healthy goats. Strong correlations (p < 0.001) were observed between Rs, sperm viability (r = 0.20), membrane integrity (r = 0.15), and acrosome integrity (r = 0.14), as well as between Xc and the same sperm parameters (r = 0.21, 0.18, and 0.16, respectively). In conclusion, our findings demonstrate that parasitic infection is associated with testicular health and subsequent epididymal sperm quality of goats. BIA can be utilized as an efficient tool to predict the impact of parasitic infection on testicular function in goats. Full article

Male infertility represents a major clinical and societal issue, with azoospermia being one of its most severe forms. Anti-Müllerian Hormone (AMH) has been proposed as a potential biomarker for predicting testicular sperm extraction (TESE) outcomes in men with non-obstructive azoospermia (NOA). This study aimed to systematically evaluate the association between AMH levels and sperm retrieval success. We included studies on men with NOA reporting TESE outcomes by AMH level, excluding those without full text or with insufficient data. When cohorts overlapped, the most complete study was used, following PICO criteria focused on AMH measurements and sperm retrieval rates (SRR). A comprehensive search identified 133 potentially relevant publications. Of these, 11 studies published between 2006 and 2023, including 1280 patients, met the inclusion criteria. Pooled analyses were performed using random-effects models. This meta-analysis was recorded in the PROSPERO database (registration ID: CRD420251065256). Reported SRRs ranged from 30.35% to 76.27%. Meta-analysis of nine studies assessing serum AMH concentrations revealed significant heterogeneity (I² = 88%). Elevated serum AMH was negatively associated with SRR (standardized mean difference [SMD] = −2.58; 95% CI: −4.73 to −0.44; p < 0.00001). In contrast, seminal plasma AMH levels (two studies) showed no significant association with SRR (I² = 82%). Similarly, preoperative FSH levels (nine studies) did not demonstrate a consistent association with SRR, despite higher mean concentrations in patients with successful TESE (p = 0.02; SMD = −4.86; 95% CI: −9.07 to −0.66). Serum AMH levels are significantly associated with TESE outcomes in men with NOA. However, the predictive value of AMH and other hormonal markers is limited by high inter-individual variability and overlapping values between successful and unsuccessful cases. These findings underscore the complexity of NOA and highlight the need to interpret hormonal markers within a broader clinical and biochemical context. Full article

The cryopreservation of limited sperm samples, especially those retrieved from patients, poses significant challenges due to the small number of viable cells available for freezing. Traditional microliter cryopreservation methods are fraught with difficulties, as thawed sperm cells become nearly impossible to locate under a microscope due to their mobility and the multiple focal planes presented by larger drops. This search time is critical, as sperm cells enter a state of decline post thaw. Conversely, when sperm cells are cryopreserved in nanoliter volumes, they can be easily discovered but do not survive the freezing and thawing processes entirely. This phenomenon is attributed to the diffusion of water molecules from the droplet into the surrounding oil, which, while designed to limit evaporation, inadvertently increases solute concentrations in the aqueous environment, leading to cellular desiccation. This article elucidates the mechanisms underlying this lethal diffusion effect and presents a novel approach for freezing in nanoliter volumes, which has demonstrated significantly improved survival rates through carefully optimized procedures in clinical trials. Our findings highlight the importance of adapting cryopreservation techniques to enhance the viability of individual sperm cells, ultimately facilitating better outcomes in assisted reproductive technologies. This study provides the first quantification of nanoscale water diffusion dynamics during cryopreservation, establishing a predictive model that explains the catastrophic loss of sperm viability and identifying the critical role of water diffusion as a major impediment for limited samples. The novelty of our results lies in both elucidating this specific mechanism of cell death and introducing a novel approach: utilizing water-saturated oil as a protective layer. This method effectively mitigates the osmotic stress caused by water loss, demonstrating remarkably improved cell survival. This work not only advances the scientific understanding of cryopreservation at the nanoscale but also offers a practical, impactful solution poised to revolutionize fertility treatments for patients with low sperm counts and holds promise for broader applications in biological cryopreservation. Full article

Purpose: The aim of this study was to investigate the effectiveness and reliability of point-of-care ultrasonography (POCUS) in the differential diagnosis of azoospermia. Materials and methods: Records of 175 patients who had previously been diagnosed with normal-volume, normal-PH azoospermia and who had undergone surgical sperm retrieval were reviewed retrospectively. Patients’ preoperative evaluations included a comprehensive history and physical examination and a routine scrotal POCUS performed during their initial consultation by a non-radiologist treating andrologist in a clinic setting. Positive scrotal imaging revealed ectasia of the rete testis and/or dilation of the epididymal ductules. Based on their preoperative assessments, patients were guided to undergo either testicular sperm aspiration (TESA)/microsurgical sperm aspiration (MESA) procedures for those with suspected obstructive azoospermia (OA) or microdissection testicular sperm extraction (micro-TESE) for those with suspected non-obstructive azoospermia (NOA). Results: Of the 175 patients, 58 patients had normal follicle-stimulating hormone (FSH) levels (≤12 IU/L) and normal testicular volume. Thirty of them had no secondary signs of obstruction in their scrotal POCUS and subsequently underwent micro-TESE. All were confirmed to have NOA. Twenty-eight patients demonstrated at least two secondary signs of obstruction on scrotal POCUS. Of these, 15 underwent TESA, and 13 underwent MESA procedures. Twenty-seven patients were confirmed to have OA, and one was confirmed as having NOA. Among this cohort of men, the sensitivity of scrotal POCUS in diagnosing OA was 100%, whereas the specificity was 96.8%. Positive and negative predictive values (PPVs and NPVs) were 96.4 and 100%, respectively. Conclusions: Scrotal POCUS is an effective clinical diagnostic tool for distinguishing obstructive and non-obstructive azoospermia. Being noninvasive, safe, and affordable makes it an ideal bedside clinical tool that can serve the skilled non-radiologist clinician reliably. Full article

Background and Objectives: Varicocele repair in men with non-obstructive azoospermia (NOA) remains a subject of debate due to inconsistent outcomes. This study aimed to evaluate the impact of microsurgical varicocelectomy on sperm recovery rates in men with NOA and to assess the role of varicocele grade and testicular histopathology in predicting postoperative outcomes. Materials and Methods: A retrospective cohort study was conducted of 78 men diagnosed with NOA and clinical varicocele who underwent microsurgical subinguinal varicocelectomy with simultaneous diagnostic and therapeutic testicular biopsy at the Department of Urology of the University of Ioannina between September 2013 and December 2021. Varicoceles were graded I to III based on physical examination and Doppler ultrasound. Histopathological patterns were classified as hypospermatogenesis (HYPO), early maturation arrest (EMA), late maturation arrest (LMA), or Sertoli cell-only syndrome (SCOS). Patients were followed postoperatively at 3, 6, 9, and 12 months, with semen analyses performed according to World Health Organization guidelines to assess sperm presence. Results: At the 12-month follow-up, spermatozoa were detected in the ejaculate of 26 out of 78 patients, resulting in an overall sperm return to ejaculate rate of 33.3%. Varicocele grade significantly influenced outcomes: patients with Grade II varicoceles had the highest sperm return to ejaculate rate (45.2%, 14/31), followed by Grade III (39.1%, 9/23) and Grade I (12.5%, 3/24) (p-value < 0.05). The sperm retrieval rate (SRR) from testicular biopsies also varied with varicocele grade: Grade II had the highest SRR (54.8%, 17/31), followed by Grade III (47.8%, 11/23) and Grade I (33.3%, 8/24). Histopathological findings were significant predictors of sperm retrieval: patients with HYPO had an SRR of 84.8% (28/33) and a sperm return to ejaculate rate of 66.7% (22/33); those with LMA had an SRR of 47.1% (8/17) and a sperm return rate of 23.5% (4/17). No sperm retrieval was observed in patients with EMA (0%, 0/4) or SCOS (0%, 0/24) (p-value < 0.01). Multivariate logistic regression identified varicocele grade and histopathology as independent predictors of sperm retrieval, with higher grades and favorable histopathology associated with increased likelihood of success. Conclusions: Microsurgical varicocelectomy can induce spermatogenesis in a significant proportion of men with NOA, particularly those with higher-grade varicoceles and favorable histopathological patterns such as HYPO or LMA. Varicocele grade and histopathological findings are important predictors of postoperative outcomes and should inform patient selection and counseling. These findings provide valuable insights for optimizing fertility treatments in men with NOA undergoing varicocele repair. Full article

Background/Objectives: Non-obstructive azoospermia (NOA) is a severe form of male infertility characterized by the absence of sperm in the ejaculate due to impaired spermatogenesis. Testicular sperm extraction (TESE) combined with intracytoplasmic sperm injection is the primary treatment, but success rates are unpredictable, causing significant emotional and financial burdens. Traditional clinical and hormonal predictors have shown inconsistent reliability. This review aims to evaluate current and emerging non-invasive preoperative predictors of successful sperm retrieval in men with NOA, highlighting promising biomarkers and their potential clinical applications. Methods: A comprehensive literature review was conducted, examining studies on clinical and hormonal factors, imaging techniques, molecular biology biomarkers, and genetic testing related to TESE outcomes in NOA patients. The potential role of artificial intelligence and machine learning in enhancing predictive models was also explored. Results: Traditional predictors such as patient age, body mass index, infertility duration, testicular volume, and serum hormone levels (follicle-stimulating hormone, luteinizing hormone, inhibin B) have limited predictive value for TESE success. Emerging non-invasive biomarkers—including anti-Müllerian hormone levels, inhibin B to anti-Müllerian hormone ratio, specific microRNAs, long non-coding RNAs, circular RNAs, and germ-cell-specific proteins like TEX101—show promise in predicting successful sperm retrieval. Advanced imaging techniques like high-frequency ultrasound and functional magnetic resonance imaging offer potential but require further validation. Integrating molecular biomarkers with artificial intelligence and machine learning algorithms may enhance predictive accuracy. Conclusions: Predicting TESE outcomes in men with NOA remains challenging using conventional clinical and hormonal parameters. Emerging non-invasive biomarkers offer significant potential to improve predictive models but require validation through large-scale studies. Incorporating artificial intelligence and machine learning could further refine predictive accuracy, aiding clinical decision-making and improving patient counseling and treatment strategies in NOA. Full article

Male infertility represents a significant global problem due to its essential health, social, and economic implications. It is unsurprising that scientific research is very active in this area and that advances in the diagnostic and therapeutic fields are notable. This review presents the main diagnostic advances in male infertility, starting from the changes made in the latest WHO Manual of semen analysis and discussing the more molecular aspects inherent to “omics”. Furthermore, the usefulness of artificial intelligence in male infertility diagnostics and the latest advances in varicocele diagnosis will be discussed. In particular, the diagnostic path of male infertility is increasingly moving towards a personalized approach to the search for the specific biomarkers of infertility and the prediction of treatment response. The treatment of male infertility remains empirical in many regards, but despite that, advances have been made to help formulate evidence-based recommendations. Varicocele, the most common correctable cause of male infertility, has been explored for expanded indications for repair. The following expanded indications were discussed: elevated sperm DNA fragmentation, hypogonadism, orchalgia, and the role of varicocele repair in non-obstructive azoospermia. Moving forward with the available data, we discussed the stepwise approach to surgical sperm retrieval techniques and the current measures that have been investigated for optimizing such patients before testicular sperm extraction. Finally, the key points and expert recommendations regarding the best practice for diagnosing and treating men with infertility were summarized to conclude this review. Full article

Immunodominant alloantigens in pig sperm membranes include 15 known gene products and a previously undiscovered Mr 20,000 sperm membrane-specific protein (SMA20). Here we characterize SMA20 and identify it as the unannotated pig ortholog of PMIS2. A composite SMA20 cDNA encoded a 126 amino acid polypeptide comprising two predicted transmembrane segments and an N-terminal alanine- and proline (AP)-rich region with no apparent signal peptide. The Northern blots showed that the composite SMA20 cDNA was derived from a 1.1 kb testis-specific transcript. A BLASTp search retrieved no SMA20 match from the pig genome, but it did retrieve a 99% match to the Pmis2 gene product in warthog. Sequence identity to predicted PMIS2 orthologs from other placental mammals ranged from no more than 80% overall in Cetartiodactyla to less than 60% in Primates, with the AP-rich region showing the highest divergence, including, in the extreme, its absence in most rodents, including the mouse. SMA20 immunoreactivity localized to the acrosome/apical head of methanol-fixed boar spermatozoa but not live, motile cells. Ultrastructurally, the SMA20 AP-rich domain immunolocalized to the inner leaflet of the plasma membrane, the outer acrosomal membrane, and the acrosomal contents of ejaculated spermatozoa. Gene name search failed to retrieve annotated Pmis2 from most mammalian genomes. Nevertheless, individual pairwise interrogation of loci spanning Atp4a–Haus5 identified Pmis2 in all placental mammals, but not in marsupials or monotremes. We conclude that the gene encoding sperm-specific SMA20/PMIS2 arose de novo in Eutheria after divergence from Metatheria, whereupon rapid molecular evolution likely drove the acquisition of a species-divergent function unique to fertilization in placental mammals. Full article

Male infertility may be caused by an impaired sperm functionality, with insufficient vitamin D levels affecting the quantity and development of motile sperm. Given the influence of vitamin D on vital aspects of male infertility, this study aimed to investigate the correlation between vitamin D levels and male infertility, along with exploring the possible mechanism of action. A total of 306 male participants were included. Semen samples were collected and analyzed for semen parameters with demographic features. Patients were classified into two groups based on vitamin D levels of <20 ng/mL (low) and ≥20 ng/mL (high). The Super-PRED, Swiss TargetPrediction, GeneCards, and DisGeNET databases were utilized to retrieve potential molecular targets associated with both vitamin D and male infertility, while the STRING database was employed for constructing protein–protein interaction (PPI) networks and conducting a functional enrichment analysis. A total of 146 patients (47.71%) showed low vitamin D levels and 160 patients (52.29%) had high vitamin D levels. Vitamin D was not strongly influenced by demographic parameters. Vitamin D demonstrated significant positive correlations with type A and B sperm motility. Conversely, it exhibited significant negative correlations with type C and D sperm motility. Hormones (thyroid-stimulating hormone, follicle-stimulating hormone, prolactin, luteinizing hormone, estradiol) were not significantly associated with vitamin D; however, testosterone was significantly positive correlated with vitamin D. Notably, no significant correlation was found between vitamin D levels and iron, ferritin, hemoglobin, hematocrit, calcium, magnesium, and phosphorus levels. The functional annotations of potential vitamin D targets associated with male infertility primarily indicated involvement in regulating infection, the immune response, forkhead box O (FOXO) and hypoxia-inducible factor 1 (HIF1) signals in male infertility. Adequate vitamin D levels are associated with an improved reproductive health, evidenced by positive correlations with hormone levels and sperm motility. Specifically, the FOXO and HIF-1 signaling pathways may be effective in the potential molecular mechanisms underlying the impact of vitamin D on male infertility and/or in the significant correlations identified. Full article

Microdissection testicular sperm extraction (mTESE) is the first-line treatment plan for nonobstructive azoospermia (NOA). However, studies reported that the overall sperm retrieval rate (SRR) was 43% to 63% among men with NOA, implying that nearly half of the patients fail sperm retrieval. This study aimed to evaluate the diagnostic performance of parameters derived from diffusion tensor imaging (DTI) in predicting SRR in patients with NOA. Seventy patients diagnosed with NOA were enrolled and classified into two groups based on the outcome of sperm retrieval during mTESE: success (29 patients) and failure (41 patients). Scrotal magnetic resonance imaging was performed, and the DTI parameters, including mean diffusivity and fractional anisotropy, were analyzed between groups. The results showed that there was a significant difference in mean diffusivity values between the two groups, and the area under the curve for mean diffusivity was calculated as 0.865, with a sensitivity of 72.2% and a specificity of 97.5%. No statistically significant difference was observed in fractional anisotropy values and sex hormone levels between the two groups. This study demonstrated that the mean diffusivity value might serve as a useful noninvasive imaging marker for predicting the SRR of NOA patients undergoing mTESE. Full article

Background: Non-obstructive azoospermia (NOA) presents a challenge in male infertility management. This study aimed to assess the efficacy of diagnostic testicular biopsy (DTB) in predicting sperm retrieval success via therapeutic testicular biopsy (TTB) and to understand the role of systemic inflammation in microdissection testicular sperm extraction (mTESE) outcomes. Methods: A retrospective analysis was conducted on 50 NOA males who underwent mTESE at the University of Ioannina’s Department of Urology from January 2017 to December 2019. All participants underwent thorough medical evaluations, including semen analyses and endocrinological assessments. Results: DTB did not detect spermatozoa in half of the patients who later showed positive sperm findings in TTB. Preoperative variables, such as age, plasma levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), total testosterone (TT), prolactin (PRL), estradiol (E2), and inflammation biomarkers (neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR), monocyte–eosinophil ratio (MER)), were not consistently predictive of sperm retrieval success. Notably, TTB-negative patients had elevated NLR and PLR values, suggesting a possible link between systemic inflammation and reduced sperm retrieval during mTESE. Conclusions: The findings question the necessity of an initial DTB, which might provide misleading results. A negative DTB should not deter further TTB or intracytoplasmic sperm injection (ICSI) attempts. The study emphasizes the need for further research to refine diagnostic approaches and deepen the understanding of factors influencing sperm retrieval in NOA patients, ultimately enhancing their prospects of biological parenthood. Full article

Klinefelter syndrome (KS), caused by the presence of an extra X chromosome, is the most prevalent chromosomal sexual anomaly, with an estimated incidence of 1:500/1000 per male live birth (karyotype 47,XXY). High stature, tiny testicles, small penis, gynecomastia, feminine body proportions and hair, visceral obesity, and testicular failure are all symptoms of KS. Endocrine (osteoporosis, obesity, diabetes), musculoskeletal, cardiovascular, autoimmune disorders, cancer, neurocognitive disabilities, and infertility are also outcomes of KS. Causal theories are discussed in addition to hormonal characteristics and testicular histology. The retrieval of spermatozoa from the testicles for subsequent use in assisted reproduction treatments is discussed in the final sections. Despite testicular atrophy, reproductive treatments allow excellent results, with rates of 40–60% of spermatozoa recovery, 60% of clinical pregnancy, and 50% of newborns. This is followed by a review on the predictive factors for successful sperm retrieval. The risks of passing on the genetic defect to children are also discussed. Although the risk is low (0.63%) when compared to the general population (0.5–1%), patients should be informed about embryo selection through pre-implantation genetic testing (avoids clinical termination of pregnancy). Finally, readers are directed to a number of reviews where they can enhance their understanding of comprehensive diagnosis, clinical care, and fertility preservation. Full article

Background: The lack of clinically useful biomarkers for predicting micro-TESE outcomes in males with idiopathic NOA. To find clinically reliable serum reproductive hormone markers to predict the outcome of sperm retrieval in men with idiopathic NOA undergoing micro-TESE. Methods: We analyzed the clinical data of 168 men with idiopathic NOA treated with micro-TESE. The clinical predictors of a successful sperm retrieval were put to the test using logistic regression analysis. The clinical net benefit was calculated using a decision-curve analysis, and the predictive power of each variable was assessed using the ROC-derived area under the curve. Result: Between positive group and negative group for sperm retrieval, there was a statistically significant difference in INHB, AMH, and INHB/AMH. AMH, INHB, and INHB/AMH were each independent predictors of successful sperm retrieval, with INHB (OR1.02, p = 0.03), AMH (OR0.85, p = 0.01), INHB/AMH (OR1.08, p < 0.01). The ROC curve determined the optimal cut-off values for serum INHB and INHB/AMH in positive sperm retrieval patients undergoing micro-TESE. 21.51 pg/mL was the cut-off value for INHB. The cut-off value for INHB/AMH was 3.19, which had a 86.3% sensitivity and a 53.8% specificity. Using INHB and INHB/AMH prior to micro-TESE sperm retrieval in idiopathic NOA patients improved the net benefit of positive sperm retrieval, and the net benefit score of INHB/AMH was better than that of INHB, according to decision analysis curves. Conclusion: Serum INHB have predictive value for sperm retrieval outcomes in idiopathic NOA patients undergoing micro-TESE. Combining INHB and AMH, INHB/AMH seems to be a better predictor. Full article