Male Fertility · Male Factor Causes
Abstract
The recent advances in assisted fertilization and gamete micromanipulation techniques have enabled fertilization in some forms of azoospermia; for example, epididymal sperm aspiration in obstructive azoospermia. Therefore knowledge of the specific degree of testicular damage is of primary importance, since other clinical parameters, such as FSH plasma levels and testicular volume, do not discriminate between the different testiculopathies. In order to further characterize the specific testicular conditions present in azoospermia, we have examined a large group of azoospermic subjects on the basis of testicular cytological analysis obtained by fine needle aspiration.
One hundred and twenty-two infertile, azoospermic men were studied by physical examination, FSH radioimmunoassay, testicular ultrasound examination and fine needle aspiration of the testes. Thirty-five infertile normozoospermic subjects were studied as controls.
The cytological analysis identified five different sub-types in azoospermic subjects: I, Sertoli cell-only syndrome; II, hypospermatogenesis; III, spermatogonial and/or spermatocytic arrest; IV, spermatidic arrest; and V, normal germ line. The testicular volume was reduced in groups I and II, while the FSH plasma levels were increased in groups I, II and III, suggesting a primary role of spermatids in the control of FSH secretion.
In azoospermic subjects, testicular cytological analysis permits the identification of different sub-types and this classification may be very important in determining therapy, particularly the choice between surgical treatment and the hypothetical use of assisted fertilization techniques by retrieval of epididymal or intratesticular spermatozoa or spermatids.
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By this author
Preimplantation genetic testing for male factor infertility: lights and shadows
Mazzilli R et al., 2026 · Journal of endocrinological investigation
Male factor could contribute, alone or in combination with female factor, to the inability to conceive in a couple in more than half of cases. The effect of male factor infertility (MFI) on embryological assisted reproductive technology (ART) outcomes remains an ongoing discussion. to evaluate the impact of MFI on embryo aneuploidy rates, to better understand the role and possible indication for Preimplantation genetic testing for aneuploidies (PGT-A), considering the role of sperm characteristics, paternal age, sperm DNA fragmentation and sperm aneuploidies. this narrative review included all available articles, published up to January 2026. Available evidence, often based on heterogeneous and old-fashioned methodologies, suggests that MFI may impair embryonic development, particularly in terms of fertilization rate and blastulation rate, more than embryo euploidy; however, a comprehensive evaluation of MFI should be integrated into clinical practice in the context of couple infertility, to also optimize the efficiency and outcomes of ART. Promising results emerged from sperm DNA fragmentation as a tool to predict embryo euploidy, but further investigations involving larger sample sizes and improved standardization are required.
Neoplastic Risk in Patients With Klinefelter Syndrome
Graziani A et al., 2026 · Andrology · Free to read
Besides gonadal involvement (hypogonadism, male factor infertility, and testicular hypotrophy), patients with Klinefelter syndrome (KS) may suffer from several extra-gonadic complications, including neoplastic events. The aim of this review is to summarize all major clinical evidence dealing with the association between KS and neoplastic diseases and provide practical suggestions for the management of patients with KS regarding neoplastic risk. This narrative review was conducted through a comprehensive search of the PubMed database, using combinations of the following keywords: "Klinefelter syndrome," "cancer," "neoplasm," "breast cancer," "germ cell tumor," "lymphoma," and "testosterone replacement therapy". KS is associated with a higher risk of breast cancer and mediastinal germ cell tumors and an apparent higher risk of hematological malignancies, in particular non-Hodgkin lymphoma and leukemia. Evidence on testicular cancer is limited, with no clear increase in risk attributable to KS, while prostate cancer has a lower risk and lower mortality rate. Given the complexity of the syndrome and the limited available evidence, regular clinical follow-up with targeted investigations when clinically indicated may facilitate early diagnosis and management of associated comorbidities.
Impact of reference gender on bone mineral density and fracture risk assessment in transgender adults
Scala A et al., 2026 · Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · Free full text on PubMed Central
In transgender adults, reference-gender choice alters Z-scores and fracture-risk estimates. Z-scores differ by 0.4-0.6 SD, with male references identifying more individuals with low BMD for age, especially in those assigned male at birth. Dual-reference reporting is advisable until further evidence becomes available. Transgender individuals, especially those assigned male at birth (AMAB), exhibit lower bone mineral density (BMD) compared with the cisgender population. Interpretation of densitometric data is challenging, as the choice of reference gender can significantly influence Z-scores and fracture risk scores. This study aims to evaluate the impact of the gender reference database (male or female) on the assessment of BMD and fracture risk in transgender adults prior to gender-affirming hormone therapy (GAHT). We conducted a cross-sectional analysis of 249 transgender individuals (153 assigned female at birth - AFAB and 96 AMAB) aged 18-43 years, recruited in the Hospitals of Padua and Brescia (Italy). Z-scores were calculated using both male and female reference databases and FRAX scores were computed using both gender inputs. Associations with anthropometric, biochemical, and hormonal parameters were explored. Z-scores differed systematically depending on the reference gender, with mean ΔZ ranging 0.4-0.6 SD across skeletal sites. Switching reference databases frequently led to reclassification of BMD status. AMAB individuals showed a higher prevalence of low BMD for age, particularly when assessed against male references (27.1%), whereas AFAB participants generally maintained normal BMD. However, FRAX scores remained low. BMI and 25-OH vitamin D levels were independent predictors of BMD and Z-scores in AMAB individuals. The choice of reference gender significantly influences densitometric interpretation in young transgender adults. Until further evidence becomes available, calculating Z-scores using both male and female reference databases is advisable. Early preventive interventions remain essential to preserve bone health.
Predictive parameters of semen outcome improvement after varicocele treatment by scleroembolization: a retrospective study
De Toni L et al., 2026 · Journal of endocrinological investigation · Free full text on PubMed Central
Varicocele is a recognized male factor of infertility. Surgical/microsurgical correction represents a therapeutical option to improve fertility outcomes but predictive parameters for the identification who can actually benefit from varicocele correction are under investigated. Here we aimed to identify baseline predictors of semen outcome improvement after varicocele treatment by scleroembolization approach. 85 patients receiving varicocele treatment by anterograde scleroembolization (ASE, N = 42) or retrograde scleroembolization (RSE, N = 43) were retrospectively recruited. Basal and 6-months follow-up evaluation of semen, hormonal and ultrasound parameters (US) were performed to address the respective effect of varicocele treatment. In addition, basal parameters were assessed as clinical outcome predictors. Varicocele grade reduction was observed in more than 90% of patients (P < 0.001). Compared to basal, significant increase of sperm concentration (10.0 ± 9.2 × 106cells/mL vs. 23.4 ± 26.9 × 106cells/mL; P < 0.001), total sperm count (TSC 39.0 ± 54.5 × 106cells vs. 70.3 ± 90.6 × 106cells, P < 0.001) and total motile sperm count (TMS, 9.8 ± 12.8 × 106cells vs. 36.7 ± 58.1 × 106cells, P < 0.001), was observed, with no differences between RSE or ASE. All US parameters were also improved (all P < 0.001). Logistic regression analysis of basal semen and ultrasound parameters showed that basal sperm motility and left testis-mean transit time (L-MTT) were associated with TSC and TMS doubling at follow-up. However, Receiver Operating Characteristic curve analysis showed that only basal L-MTT basal sperm was consistently associated with TSC and TMS doubling at follow-up (respectively: AUC = 0.834, CI: 0.747-0.921 and AUC = 0.805, CI: 0.708-0.901; both P < 0.001). Baseline sperm count and US parameters represent useful clinical descriptors to address those subjects eligible for varicocele correction.
Related research
Testicular fine needle aspiration as a diagnostic tool in non-obstructive azoospermia
Bettella A et al., 2005 · Asian journal of andrology · Free to read
To report the fine needle aspiration cytology (FNAC) of the testes used as a diagnostic tool in non-obstructive azoospermic patients. One hundred and twenty-five non-obstructive azoospermic male candidates to intracytoplasmic sperm injetion (ICSI) were analysed for follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone and inhibin B plasma levels. They were classified into three groups on the basis of 1) Sertoli cell-only syndrome (SCOS) (70); 2) severe hypospermatogenesis (42); and 3) maturation arrest (13). Then, all men underwent testicular sperm extraction (TESE) for sperm recovery for ICSI. Mature spermatozoa were detected by FNAC in 24 of 42 men with severe hypospermatogenesis and nine of 13 men with maturation arrest; while they were retrieved by TESE in 29 of 70 men with SCOS, 35 of 42 men with severe hypospermatogenesis (including the 24 by FNAC) and 10 of 13 men with maturation arrest (including the nine by FNAC). The sensitivity and specificity of FNAC were 44.6 % and 100 %, respectively. There was no difference on testicular volume and hormonal parameters in men with and without sperm retrieved. These findings suggest that FNAC may be a simple and valid diagnostic parameter in non-obstructive azoospermic men and it may represent a valid positive prognostic parameter for sperm recovery at TESE.
FSH in the treatment of oligozoospermia
Foresta C et al., 2000 · Molecular and cellular endocrinology
The aim of this study was to individuate parameters able to distinguish oligozoospermic subjects who will respond to follicle-stimulating hormone (FSH) therapy. A group of 135 oligozoospermic subjects was divided in three groups considering basal FSH and inhibin B concentrations: group A (normal FSH and inhibin B) characterized by moderate hypospermatogenesis sometimes associated to partial spermatidic arrest; group B (high FSH and normal inhibin B) characterized by hypospermatogenesis associated or not to spermatogonial/spermatocytic arrest; group C (high FSH and low inhibin B) characterized by severe hypospermatogenesis. Seventy-eight patients were treated with FSH at the dose of 75 IU on alternate days while 57 were treated with the same dose every day for 3 months. After FSH treatment a significant increase in ejaculated sperm concentration was observed only in oligozoospermic subjects with normal basal FSH and inhibin B plasma levels (group A) showing a testicular cytological picture of moderate hypospermatogenesis. In these subjects no differences in sperm production were observed between the two protocols of therapy. In the remaining patients of group A, characterized by hypospermatogenesis associated with maturation arrest at spermatidic level and in group B and C, no increase in sperm concentration was observed after therapy. These data suggest that FSH treatment may have a role in oligozoospermic subjects only when the spermatogenetic alterations consist in germ cell depopulation without maturative disturbances and with normal FSH concentrations.
Evidence for a stimulatory role of follicle-stimulating hormone on the spermatogonial population in adult males
Foresta C et al., 1998 · Fertility and sterility
To evaluate the effects of treatment with FSH on seminal indices and on the seminiferous epithelium of oligozoospermic subjects with normal FSH plasma levels. Placebo-controlled, double-blind randomized study. Academic setting. PATIENT(S): Ninety subjects with idiopathic oligozoospermia (sperm count of < 10 x 10(6)/mL) and normal plasma levels of FSH. INTERVENTION(S): Three months of treatment with FSH (60 patients) or placebo (30 patients); bilateral testicular fine-needle aspiration. MAIN OUTCOME MEASURE(S): Seminal indices; testicular cytologic features; plasma levels of FSH, LH, and testosterone; and ultrasonographic testicular examination. RESULT(S): According to seminal indices, patients treated with FSH and placebo were classified as nonresponders or as responders (as determined by at least a doubling of sperm count). No placebo-treated patients responded to treatment. Among FSH-treated patients, 20 responded to hormonal treatment and 40 did not. The results of pretreatment cytologic examination of testicular specimens from patients who did not respond to FSH treatment were consistent with hypospermatogenesis associated with maturational disturbances at the spermatid level. In contrast, patients who responded to treatment with FSH had isolated hypospermatogenesis without maturational disturbances. After FSH therapy, we detected an increase of spermatogonia and spermatocyte population in both the responder and nonresponder subjects. This increase was associated with an activation of spermatogenic and spermiogenic processes and with a rise in ejaculated sperm concentration only when isolated hypospermatogenesis was present (responder patients). CONCLUSION(S): The findings of this study demonstrate that FSH treatment increases the spermatogonial population in men. This treatment may be appropriate for oligozoospermic subjects who have normal FSH plasma levels and a testicular evaluation characterized by hypospermatogenesis without maturational disturbances.
Doppler ultrasound of the testis in azoospermic subjects as a parameter of testicular function
Foresta C et al., 1998 · Human reproduction (Oxford, England)
Azoospermia frequently represents the end-point of different pathological conditions that cause important quantitative and qualitative alterations of both spermatogenesis and testicular structure, including intratesticular blood vessels. In this study we performed colour Doppler ultrasound of the testis in 12 azoospermic subjects affected by primary testicular pathology (four bilateral post-orchitis, four postradiotheraphy for cancer, four post-traumatic) aged 28.2+/-3.3 (mean+/-SD) years, in six subjects affected by obstructive azoospermia aged 29.7+/-2.4 years and in 20 age-matched fertile subjects (aged 28.6+/-2.5 years). The analysis of intratesticular vessels per organ was quantified using a semiquantitative score: category 0, no vessels visible; category 1, between one and three intratesticular vessels visible; and category 2, more than three vessels visible. In obstructive azoospermic patients and in fertile subjects there were always more than three intratesticular vessels. No intratesticular vessels were detected in eight testes (33.3%) and fewer than three vessels in 16 testes (66.6%) in subjects affected by primary testicular pathology. In azoospermic subjects the testicular structure of the testis was evaluated by diagnostic fine needle aspiration cytology (FNAC) performed in the middle portion of the testis. In non-obstructive azoospermic patients this procedure showed the presence of only Sertoli cells in all cases. When detectable vessels were present, a new aspiration was performed in these areas. In 12 out of 16 cases, spermatogenetic cells including mature spermatozoa, were found when the FNAC was performed in testicular regions showing the presence of blood vessels. These results indicate that colour Doppler sonography of the testis may be useful in the differential diagnosis of azoospermia and suggest the evaluation of the intratesticular blood vessel distribution before performing any method to retrieve intratesticular spermatozoa for intracytoplasmic sperm injection.