Male Fertility · Male Endocrine and Genetic Factors
Suppression of the high endogenous levels of plasma FSH in infertile men are associated with improved Sertoli cell function as reflected by elevated levels of plasma inhibin B
Foresta C,Bettella A,Spolaore D,Merico M,Rossato M,Ferlin A
Published April 29, 2004Human reproduction (Oxford, England)
In vitro continuous stimulation of Sertoli cells with FSH leads to a desensitization of these cells to FSH action. To evaluate the presence of a desensitization of FSH receptor on Sertoli cells in vivo, we performed a controlled clinical study in 97 men affected by severe oligozoospermia.
Methods
On the basis of FSH and inhibin B plasma concentrations, these subjects were divided into three groups: group A, 33 subjects with high FSH and low inhibin B plasma levels; group B, 32 subjects with high FSH plasma levels and inhibin B concentrations at the lower limit of the normal range; and group C, 32 subjects with normal FSH and inhibin B plasma levels. Patients with high FSH plasma levels (groups A and B) were prospectively randomized into two subgroups, called A1, A2, B1 and B2. Patients of groups A1 and B1 were treated with a GnRH agonist, leuprolide acetate, to induce a hypogonadotrophic state and then were treated with recombinant human FSH (r-hFSH; 100 IU/day) and hCG (2000 IU/twice a week) for 2 months. Subjects of groups A2, B2 and C were treated only with r-hFSH for the same period.
Results
In patients of group A1, inhibin B remained unmodified during the whole period of study, whereas in subjects of group B1, we observed a significant reduction of this hormone during the hypogonadotrophic period and then an increase of inhibin B plasma levels that were higher that those observed before therapy. In patients of groups A2 and B2, FSH treatment did not induce a significant increase in inhibin B concentrations. In patients of group C, FSH induced a significant increase in inhibin B plasma levels.
Conclusions
In infertile men, suppression of the high endogenous levels of plasma FSH associated with much lower exogenous FSH levels is able to evoke higher inhibin B production, which may indicate improved Sertoli cell function and the possibility that this could have a positive effect on spermatogenesis.
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.
Grande G et al., 2026·The Journal of clinical endocrinology and metabolism·Free to read
Male factor infertility (MFI) is frequently labelled idiopathic when evaluation relies primarily on semen analysis, potentially overlooking endocrine and pathophysiological mechanisms relevant for targeted management.
To phenotypically define MFI and develop a pathophysiology-based classification aimed at reducing idiopathic infertility following comprehensive evaluation.
Prospective monocentric cohort study conducted at a tertiary referral academic centre.
Eight hundred male partners of infertile couples evaluated between October 2024 and January 2026 after exclusion of isolated female factor infertility.
Prevalence of MFI categories, hormonal patterns across phenotypes, and proportion of idiopathic infertility after comprehensive work-up.
All patients underwent standardized clinical evaluation, hormonal assessment (total testosterone, FSH, LH), testicular ultrasound, and complete semen analysis. Microbiological testing, transrectal ultrasound, and genetic analyses were performed according to guidelines.
Primary spermatogenic failure was the most prevalent category (56.0%), followed by infection/inflammation (22.4%) and hypogonadotropic hypogonadism (8.5%). Idiopathic infertility was identified in only 5.3% of cases. Distinct endocrine profiles were observed, with high-FSH spermatogenic failure representing the dominant phenotype.
Comprehensive phenotyping markedly reduces the proportion of patients classified as having idiopathic infertility and identifies clinically relevant subgroups. This prospective study provides validation of a pathophysiology-based classification and supports a shift toward endocrine-integrated diagnostic strategies in male infertility, with potential implications for targeted management.
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.
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.
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.
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.
Male Endocrine and Genetic Factors · Genetic Causes of Male Infertility
Foresta C et al., 2002·European journal of endocrinology
The DAZ (deleted in azoospermia) gene family on the Y chromosome long arm is the major candidate for the AZFc (azoospermia factor c) phenotype of male infertility and it is expressed only in germ cells. The aim of the study was to assess Sertoli cell function in subjects with AZFc deletions.
Case-control, prospective study.
We have studied six severely oligozoospermic subjects with AZFc-DAZ deletions, and looked whether they responded in terms of inhibin B production to a 1 month FSH treatment. These patients were compared with three groups of patients affected by different spermatogenic alterations not related to deletions on the Y chromosome.
Although affected by severe testiculopathy, patients with AZFc-DAZ deletions had only slightly elevated FSH, and normal inhibin B plasma concentrations. Inhibin B responded normally during FSH treatment, supporting the hypothesis that Sertoli cells are not altered. On the contrary, other severe testiculopathies not related to Y chromosome deletions showed high FSH and low inhibin B concentrations, with no response to FSH treatment. In these cases the cause of the spermatogenic defect probably damaged both germ and Sertoli cells. Finally, idiopathic patients with a hormonal status similar to Y-deleted patients (slightly elevated FSH and normal inhibin B concentrations) did not respond to FSH treatment, suggesting that Sertoli cells were already at their maximal functional capability.
These data confirm that Sertoli cell function is not damaged in patients with AZFc-DAZ deletions and that the strong reduction of germ cells does not affect the FSH-inhibin B feedback loop.
To evaluate the effects of treatment with recombinant human FSH (r-hFSH) on seminal parameters and seminiferous epithelium in idiopathic patients with oligozoospermia with normal FSH plasma levels.
Randomized single-blind study.
Academic setting.
PATIENT(S): Forty-five subjects with idiopathic oligozoospermia (sperm count <10 x 10(6)/mL) and normal FSH and inhibin B plasma levels.
INTERVENTION(S): Three months of treatment with r-hFSH 50 IU (15 patients) or with r-hFSH 100 IU on alternate days (15 patients) or no treatment (15 patients); bilateral testicular fine-needle aspiration (FNA) performed before and after therapy; FSH and inhibin B plasma levels evaluated during treatment.
MAIN OUTCOME MEASURE(S): Seminal parameters; testicular cytological features evaluated by FNA; plasma levels of FSH, LH, T, and inhibin B.
RESULT(S): Treatment with r-hFSH at a dose of 50 IU induced no increase in sperm concentration, while treatment with r-hFSH at a dose of 100 IU induced a significant increase in sperm concentration. In particular, in 11/15 patients a doubling of the pretreatment sperm concentration was observed. No significant increase in sperm parameters was observed in the control group. In both groups of patients treated with r-hFSH, the cytological analysis before treatment showed hypospermatogenesis. An increase in the percentage of spermatogonia and spermatocytes was observed only after the treatment with r-hFSH at a dose of 100 IU.
CONCLUSION(S): The findings of this study demonstrate that r-hFSH at a dose of 100 IU, as previously seen with highly purified FSH, increases the spermatogonial population and sperm production in idiopathic patients with oligozoospermia with normal FSH and inhibin B plasma levels and a cytological picture of hypospermatogenesis.
Male Fertility › Male Endocrine and Genetic Factors › Male Hormonal Axis · Therapeutics › Hormonal Agents › Gonadotropins
PMID 15117900 15117900 DOI 10.1093/humrep/deh255 10.1093/humrep/deh255 Foresta et al. 2004, Foresta 2004
00240q980