Search Results (77)

Azoospermia represents the most severe manifestation of male infertility and is classified into obstructive azoospermia (OA) and non-obstructive azoospermia (NOA). NOA patients experience a lack of sperm due to testicular dysfunction, posing significant challenges in clinical diagnosis and treatment. Recent advancements in molecular biology and high-throughput technologies have led to the discovery and validation of numerous biomarkers, including proteins, non-coding RNAs, genetic polymorphisms, and imaging indicators, which have greatly enhanced the understanding of the pathophysiological mechanisms of azoospermia and facilitated non-invasive diagnostic approaches. This review aims to systematically summarize the pathogenesis of azoospermia and critically evaluate the latest advancements in diagnostic and prognostic biomarkers, including small RNAs, proteomic profiles, genetic markers, and imaging features. The overarching goal is to synthesize this knowledge toward the development of integrated, biomarker-guided strategies for precise diagnosis, prognosis prediction, and improved clinical management of azoospermia, particularly NOA. Full article

Non-obstructive azoospermia (NOA), a severe male infertility condition with impaired or absent sperm production, is treated by microsurgical testicular sperm extraction (micro-TESE), whose success depends on identifying seminiferous tubules with active spermatogenesis. To address this challenge, we demonstrate that mid-infrared photothermal (MIP) microscopy can provide label-free molecular signatures to distinguish different NOA subtypes in patient tissues. We applied MIP microscopy and MIP-guided IR spectroscopy to testicular tissues from obstructive azoospermia (normal spermatogenesis) and idiopathic NOA (abnormal spermatogenesis) patients. Tissue classification was performed using a Singular Value Decomposition–Random Forest (SVD-RF) pipeline. MIP imaging revealed distinct lipid distribution and reduced lipid content in NOA tissues compared to normal spermatogenic tissues. Using SVD to extract spectroscopic features and RF for classification, we achieved 94.03% accuracy in distinguishing testicular tissues as normal spermatogenesis or three pathological subtypes of idiopathic NOA. These findings demonstrate MIP microscopy as an effective tool for characterizing the spermatogenic potential of seminiferous tubules based on their molecular composition, potentially facilitating improved sperm retrieval strategies. Full article

In idiopathic azoospermia caused by non-obstructive infertility with AZFc deletion, the testicle usually contains an increased number of mast cells (MCs)—which are responsible for collagen synthesis in the testes—as well as Leydig cell hyperplasia. However, the relationship between MCs and telocytes in this pathology remains unexplored. The aim of this study was to examine ultrastructural changes in the interstitial tissue microenvironment of the convoluted seminiferous tubules in the testis, using clinical specimens from men with genetically determined non-obstructive infertility with AZFc deletion. Histological, immunohistochemical, and electron microscopic (EM) studies were performed on surgical materials from 14 patients with AZFc deletion. The IHC study was performed using a panel of antibodies: tryptase, chymase, carboxypeptidase A3, and αSMA. The EM study was performed on ultrathin sections with a thickness of 100–120 nm. MCs were found to be in a functionally active state and characterized by a variety of secretory activities. For the first time, telocytes and their colocalization with MCs and Leydig cells were visualized. It is possibly the telocytes—interacting with MCs—that synchronize the functional activity of the entire MC population of the testis. The interaction of MCs with telocytes, as well as individual secretory granules associated with loci of tropocollagen and collagen microfibril accumulation, leads to the accumulation of collagen fibrils in the interstitium, as observed in idiopathic infertility with AZFc deletion. Even with a small number of MCs in the interstitium of the convoluted seminiferous tubules in the testis, the telocytes are able to synchronize MCs’ activation and secretory activity, supporting the development of a profibrotic phenotype of the tissue microenvironment. The obtained results advance our understanding of idiopathic infertility with AZFc deletion by delineating the ultrastructural landscape of the testicular interstitium and establishing telocytes as key regulators of cellular crosstalk. Telocytes use complex mechanisms for the spatial integration of MCs and fibroblasts in the profibrotic phenotype formation of the convoluted seminiferous tubule tissue microenvironment. Potentially, telocytes can directly be involved in synchronizing such processes by activating the biogenesis and secretion of collagen monomers by fibroblasts; the MC secretome directly affects the polymerization of collagen monomers and dimers into microfibrils in the extracellular matrix, stimulating excessive collagen fiber formation and the development of fibrotic changes. 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

Background/Objectives: Hypogonadotropic hypogonadism (HH) is an uncommon but treatable cause of non-obstructive azoospermia (NOA). Fertility can often be restored with gonadotropin therapy. This study evaluated spermatogenic and reproductive outcomes in men with HH-related NOA managed by stepwise gonadotropin therapy, microdissection testicular sperm extraction (microTESE) for persistent azoospermia, and assisted reproduction when indicated. Methods: A retrospective cohort study included 35 men treated between 2010 and 2022. Human chorionic gonadotropin (hCG), with or without follicle-stimulating hormone (FSH), was administered to induce spermatogenesis. Outcomes included sperm appearance in the ejaculate, microTESE sperm retrieval rate in persistent azoospermia, and pregnancy and live birth outcomes after natural conception or in vitro fertilization with intracytoplasmic sperm injection (IVF-ICSI) when required. Results: Mean gonadotropin therapy duration was 12.0 months (range 6–24). Sperm appeared in the ejaculate in 27/35 men (77%). The remaining 8/35 (23%) underwent microTESE, with sperm retrieved in 7/8 (88%). Seven couples proceeded to IVF-ICSI, undergoing 11 cycles that yielded 6 clinical pregnancies (55% per cycle) and 5 live birth deliveries, including 2 twin pregnancies. Among responders, 13 natural pregnancies occurred, resulting in 13 live birth deliveries, including 2 twin pregnancies. Overall, 18/35 men (51%) achieved biological fatherhood, corresponding to 18 live birth delivery events (4 twin and 14 singleton deliveries) and 22 newborns. Conclusions: In men with HH-related NOA, exogenous gonadotropin therapy is expected to induce spermatogenesis in most patients. MicroTESE provides high sperm retrieval rates for those without ejaculatory sperm. Through an integrated approach of hormonal induction, microsurgical sperm retrieval, and assisted reproduction, approximately half of patients may ultimately achieve biological fatherhood in longer-term follow-up, depending on baseline severity and partner factors. Full article

Non-obstructive azoospermia (NOA) is a severe male infertility condition characterized by extremely low or absent sperm production. In microdissection testicular sperm extraction (Micro-TESE) procedures for NOA, embryologists must manually search through testicular tissue under a microscope for rare sperm, a process that can take 1.8–7.5 h and impose significant fatigue and burden. This paper presents an augmented reality (AR) microscope system with AI-based image analysis to accelerate sperm retrieval in Micro-TESE. The proposed system integrates a deep learning model (YOLOv5) for real-time sperm detection in microscope images, a multi-object tracker (DeepSORT) for continuous sperm tracking, and a velocity calculation module for sperm motility analysis. Detected sperm positions and motility metrics are overlaid in the microscope’s eyepiece view via a microdisplay, providing immediate visual guidance to the embryologist. In experiments on seminiferous tubule sample images, the YOLOv5 model achieved a precision of 0.81 and recall of 0.52, outperforming previous classical methods in accuracy and speed. The AR interface allowed an operator to find sperm faster, roughly doubling the sperm detection rate (66.9% vs. 30.8%). These results demonstrate that the AR microscope system can significantly aid embryologists by highlighting sperm in real time and potentially shorten Micro-TESE procedure times. This application of AR and AI in sperm retrieval shows promise for improving outcomes in assisted reproductive technology. 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

Background/Objectives: Approximately 50% of infertility cases are attributable to male factors; yet conventional semen examination can not identify the molecular abnormalities that hinder sperm functionality. Extracellular vesicles (EVs) derived from sperm, such as testicular EVs, prostasomes, and epididymosomes, have become important modulators of oocyte activation, sperm maturation, capacitation, acrosome stability, motility, and early embryonic development. This study aimed to evaluate the potential diagnostic and translational uses of sperm-associated extracellular vesicles (EVs) in male infertility and assisted reproduction, while also consolidating recent insights on their origins, composition, and functional significance. Methods: A focused narrative search of PubMed (2000–2025) was conducted using backward and forward citation tracking. Studies that qualified included human clinical cohorts, functional sperm extracellular vesicle tests, and omics analyses using MISEV-aligned extracellular vesicle isolation and characterisation methodologies. When human mechanistic understanding was constrained, knowledge from animal research was selectively integrated. Results: The cargo signatures specific to the source identified in sperm-derived and seminal EVs encompass proteins, small RNAs, lipids, and enzymatic modules that govern sperm maturation, capacitation, acrosome reaction, redox balance, calcium signalling, zona binding, and DNA integrity. Density-resolved seminal extracellular vesicle subfractions (EV-H/EV-M/EV-L) have unique functional and proteomic characteristics linked to progesterone-induced hyperactivation, oxidative stress, and motility. Asthenozoospermia and oligoasthenoteratozoospermia are associated with changes in extracellular vesicle composition, reduced embryonic developmental potential, compromised oocyte activation (related to PLCζ), and increased sperm DNA fragmentation. Numerous EV-related miRNA and protein signatures may predict TESE results, identify functional sperm anomalies not recognised by conventional semen analysis, and differentiate between obstructive and non-obstructive azoospermia. Conclusions: The available findings indicate that sperm-derived extracellular vesicles are significant functional regulators of sperm physiology and may serve as valuable non-invasive indicators for male infertility. The standardisation of EV isolation, characterisation, and clinical validation is essential prior to widespread use; nonetheless, their integration into liquid biopsy methods and assisted reproductive technology processes represents a significant improvement. Full article

Background and Objectives: Currently, infertility is one of the major problems affecting up to 12% of couples worldwide, with more than a quarter of cases being male-related. It is assumed that Leukocyte-poor platelet-rich plasma (LP-PRP) can improve the function of germ cells and serve as a regenerative substrate as a source of biologically active substances that play an important role in the process of spermatogenesis in infertile men. We aimed to evaluate the proliferation, apoptosis, and growth factors of germ cells after the administration of LP-PRP in patients with non-obstructive azoospermia. Materials and Methods: The study used archival material (paraffin blocks of testicular biopsies) of patients with non-obstructive azoospermia aged 21–34 years (n = 41; associated diagnosis: varicocele). We confirm that no interventions or biopsies were performed as part of the study itself. They were injected bilaterally into the spermatic cord and in the region of the lower pole of the testis under ultrasound control were injected with PRP once a week for 6 weeks. Biopsies were immunohistochemical reactions with antibodies to Ki-67, Bcl-2, caspase 3 and p53, IGF-1, TGF-β, and VEGF-A. Results: Immunohistochemical study of testicular biopsies after LP-PRP injection revealed an increase in the number of cells stained for proliferation proteins (Ki-67) and anti-apoptosis (Bcl-2), IGF-1, TGF-β, VEGF-A; decrease caspase-3- and p53-positive cells. Conclusions: In LP-PRP, platelet α-granule growth factors, which are key regulators of the cell cycle of germ cells, demonstrate restoration of the proliferative-apoptotic balance, confirmed by the expression levels of Ki-67, Bcl-2, caspase 3, and p53 in patients with non-obstructive azoospermia. In human testicular biopsies, the administration of LP-PRP led to an exponential release of numerous growth factors from platelet α-granules, which, based on their regenerative properties, improved the morphological and immunohistochemical picture of the germinal epithelium in non-obstructive azoospermia. Full article

Background/Objectives: Male infertility is a major health concern with a complex etiopathology, yet a substantial proportion of cases remain idiopathic. Mitochondrial dysfunction and non-coding RNA (ncRNA) deregulation have both been implicated in impaired spermatogenesis, but their interplay remains poorly understood. This study aimed to identify infertility-specific variants in ncRNAs that affect mitochondrial dynamics and homeostasis and to explore their roles. Methods: Whole-genome sequencing (WGS) was performed on genomic DNA samples from teratozoospermic, asthenozoospermic, oligozoospermic, and normozoospermic men. Variants uniquely present in infertile individuals and mapped to ncRNAs that affect mitochondrial dynamics were selected and prioritized using bioinformatics tools. An independent transcriptomic validation was conducted using RNA-sequencing data from testicular biopsies of men with non-obstructive azoospermia (NOA) to determine whether the ncRNAs harboring WGS-derived variants were transcriptionally altered. Results: We identified several infertility-specific variants located in lncRNAs known to interact with mitochondrial regulators, including GAS5, HOTAIR, PVT1, MEG3, and CDKN2B-AS1. Transcriptomic analysis confirmed significant deregulation of these lncRNAs in azoospermic testicular samples. Bioinformatic analysis also implicated the disruption of lncRNA–miRNA–mitochondria networks, potentially contributing to mitochondrial membrane potential loss, elevated reactive oxygen species (ROS) production, impaired mitophagy, and germ cell apoptosis. Conclusions: Our integrative genomic and transcriptomic analysis highlights lncRNA–mitochondrial gene interactions as a novel regulatory layer in male infertility, while the identified lncRNAs hold promise as biomarkers and therapeutic targets. However, future functional studies are warranted to elucidate their mechanistic roles and potential for clinical translation in reproductive medicine. Full article

Varicocele is a common, potentially correctable condition associated with impaired male fertility. Despite being frequently encountered in clinical andrology, its pathophysiological mechanisms, diagnostic criteria, and therapeutic approaches remain areas of active investigation and debate. The authors conducted a comprehensive literature search, using the PubMed database, covering clinical studies, systematic reviews, meta-analyses, and current international guidelines from the past ten years. Emphasis was placed on studies investigating novel diagnostic modalities, therapeutic innovations, and prognostic markers. Emerging evidence supports the multifactorial pathophysiology of varicocele, involving oxidative stress, hypoxia, inflammatory pathways, and potential genetic predisposition. Biomarkers, including microRNAs, antisperm antibodies, and sperm DNA fragmentation, offer diagnostic and prognostic utility, though their routine clinical implementation requires further validation. Advances in imaging, such as shear wave elastography, may improve diagnostic accuracy. While microsurgical subinguinal varicocelectomy remains the gold standard, technological refinements and non-surgical alternatives are being explored. Indications for treatment have expanded to include selected cases of non-obstructive azoospermia, hypogonadism, and optimization for assisted reproduction, though high-level evidence is limited. Full article

Male-factor infertility accounts for approxiamately half of all infertility cases globally, yet therapeutic options remain limited for individuals with no retrievable spermatozoa, such as those with non-obstructive azoospermia (NOA). In recent years, artificial gametogenesis has emerged as a promising avenue for fertility restoration, driven by advances in two complementary strategies: organotypic in vitro spermatogenesis (IVS), which aims to complete spermatogenesis ex vivo using native testicular tissue, and in vitro gametogenesis (IVG), which seeks to generate male gametes de novo from pluripotent or reprogrammed somatic stem cells. To evaluate the current landscape and future potential of these approaches, a narrative, semi-systematic literature search was conducted in PubMed and Scopus for the period January 2010 to February 2025. Additionally, landmark studies published prior to 2010 that contributed foundational knowledge in spermatogenesis and testicular tissue modeling were reviewed to provide historical context. This narrative review synthesizes multidisciplinary evidence from cell biology, tissue engineering, and translational medicine to benchmark IVS and IVG technologies against species-specific developmental milestones, ranging from rodent models to non-human primates and emerging human systems. Key challenges—such as the reconstitution of the blood–testis barrier, stage-specific endocrine signaling, and epigenetic reprogramming—are discussed alongside critical performance metrics of various platforms, including air–liquid interface slice cultures, three-dimensional organoids, microfluidic “testis-on-chip” devices, and stem cell-derived gametogenic protocols. Particular attention is given to clinical applicability in contexts such as NOA, oncofertility preservation in prepubertal patients, genetic syndromes, and reprocutive scenarios involving same-sex or unpartnered individuals. Safety, regulatory, and ethical considerations are critically appraised, and a translational framework is outlined that emphasizes biomimetic scaffold design, multi-omics-guided media optimization, and rigorous genomic and epigenomic quality control. While the generation of functionally mature sperm in vitro remains unachieved, converging progress in animal models and early human systems suggests that clinically revelant IVS and IVG applications are approaching feasibility, offering a paradigm shift in reproductive medicine. Full article

Purpose: Non-obstructive azoospermia (NOA) presents major challenges in assisted reproductive technology (ART) due to the extremely low number of viable sperm within testicular tissue. In Micro-TESE procedures, embryologists manually search for sperm under DIC microscopy—a slow, labor-intensive process. We aim to streamline this process with an efficient computational detection tool. Methods: We present SD-CLIP (Sperm Detection using Classical Image Processing), a lightweight, real-time algorithm that simulates sperm structure detection from unstained DIC images. The model first identifies convex sperm head candidates based on shape and width using edge gradients, then confirms the presence of a tail via principal component analysis (PCA) of pixel clusters. Results: Compared to the MB-LBP + AKAZE method, SD-CLIP improved processing speed by 4× and achieved a 3.8× higher posterior probability ratio, making detected sperm candidates significantly more reliable. Evaluation was performed on both human Micro-TESE and mouse testis images, demonstrating robustness in low-sperm environments. Conclusions: SD-CLIP simulates a domain-specific image interpretation model that identifies sperm morphology with high specificity. It requires minimal computational resources, supports real-time integration, and could be extended to automated sperm extraction systems. This tool has clinical value for accelerating Micro-TESE and increasing success rates in ART for NOA patients. 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

PIWI-interacting RNAs (piRNAs) are small noncoding RNAs that are almost exclusively expressed in germ cells to silence harmful transposons to maintain genome stability. PIWIL4 is guided by its associated piRNAs to transposable elements, where it recruits the DNA methylation apparatus and instructs de novo DNA methylation. Herein, we identified a missense variant of PIWIL4 (c.805 C>T p.R269W) in two infertile males. Homozygous male mice carrying the orthologous knock-in variant displayed elevated transposable element expression and aberrant gene expression during the first wave of spermatogenesis, despite exhibiting normal sperm counts and morphology. Mechanistically, the mutated site altered the piRNA-binding ability of PIWIL4 and led to the derepression of endogenous LINE-1 elements. In summary, we identified a piRNA binding mutation in PIWIL4 that may be involved in human nonobstructive azoospermia. Full article