FSH improves sperm in only some men with unexplained infertility
A 2024 narrative review reports that FSH raised sperm counts and pregnancy rates in only some men with infertility of unknown cause. The authors estimate 10 to 18 men need treatment for one extra pregnancy. Hormone levels, testicular cells and genes have been proposed as predictors of response.
Key Findings
Four meta-analyses cited in the review linked FSH treatment in men with unexplained infertility to higher pregnancy rates, less sperm DNA fragmentation and higher sperm concentrations.
Among men with unexplained infertility, the number who must be treated to gain one more pregnancy is estimated at between 10 and 18.
Non-responders may make up about 50% of men with normal pituitary hormone levels in plasma.
According to the available data, a low baseline FSH level is the only biochemical parameter that might predict response. Studies so far have not suggested efficacy at higher baseline levels.
Studies of FSHB and FSHR gene variants as response predictors gave conflicting results, so their clinical use remains unclear.
Interpretation
The paper calls itself a narrative review, and its authors write that the level of evidence is low. They name limits in the underlying studies: unstandardized FSH use, mixed patient groups and different treatment lengths. In men with unexplained infertility, the cited meta-analyses linked FSH to better sperm measures and pregnancy. Several studies on spermatid count, testicular cytology and gene variants come from the authors' own group. The post-genomic marker studies used rat and pig cells, and the authors say they still need translation to clinical practice.
RRM Context
The authors report that 20 to 50% of male infertility cases have no definite cause. They say the label "idiopathic" belongs only after a thorough diagnostic workup. Restorative reproductive medicine treats such cases as undiagnosed. Male factor infertility is present in 10 to 15% of couples worldwide, alone or with a female factor. A couple-centered workup evaluates both partners.
Our editorial summary of this paper, not the article's abstract.
Abstract
Follicle-stimulating hormone (FSH) administration is applied in the management of subjects affected by hypogonadotropic hypogonadism. Whilst this application is widely recognized and established alone or in combination with human chorionic gonadotropin (hCG), a similar strategy is empirically advocated in idiopathic male factor infertility (MFI). In this setting, FSH therapy has been used to increase sperm quantity, quality, and pregnancy rate when FSH plasma concentrations are below 8 IU/L and when the seminal tract is not obstructed. In the literature, several studies suggested that giving FSH to patients with idiopathic MFI increases sperm count and motility, raising the overall pregnancy rate. However, this efficacy seems to be limited, and about 10-18 men should be treated to achieve one pregnancy. Thus, several papers suggest the need to move from a replacement approach to an overstimulating approach in the management of FSH therapy in idiopathic MFI. To this aim, it is imperative to determine some pharmacologic markers of FSH efficacy. Furthermore, it should be useful in clinical practice to distinguish, before starting the treatment, among patients who might respond or not to FSH treatment. Indeed, previous studies suggest that infertile men who have normal levels of gonadotropins in plasma might not respond to FSH treatment and about 50% of patients might be defined as "non-responders". For these reasons, identifying predictive markers of FSH action in spermatogenesis and clinical markers of response to FSH treatment is a fascinating area of study that might lead to new developments with the aim of achieving personalization of the treatment of male infertility. From this perspective, seminal parameters (i.e., spermatid count), testicular cytology, genetic assessment, and miRNA or protein markers in the future might be used to create a tailored FSH therapy plan. The personalization of FSH treatment is mandatory to minimize side effects, to avoid lost time with ineffective treatments, and to improve the efficacy, predicting the most efficient dose and the duration of the treatment. This narrative review's objective is to discuss the role of the different putative factors which have been proposed to predict the response to FSH treatment in idiopathic infertile men.
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.
Rocca MS et al., 2026·Journal of translational medicine·Free to read
Standard semen analysis has little prognostic value in distinguishing fertile from infertile men. Furthermore, in men with semen parameters within the reference ranges, it cannot distinguish fertile men from infertile men, i.e. partners of couples with idiopathic infertility. Oxidative stress, mitochondrial dysfunction, sperm telomere shortening, and DNA fragmentation have been proposed as contributors to impaired male fertility. However, these biomarkers have not been evaluated as a whole in subjects with normal semen parameters, partners of fertile and infertile couples.
To characterise a multidimensional panel of sperm biomarkers-including sperm telomere length (STL), mitochondrial DNA copy number (mtDNAcn), reactive oxygen species (ROS), lipid peroxidation (LP), sperm chromatin dispersion (SCD), and respiratory control ratio (RCR)-and to identify whether these parameters might discriminate, in men with normal semen parameters, infertile men from fertile controls.
A total of 150 men with semen parameters within the normal ranges were enrolled: 47 male partners of couples with idiopathic infertility and 103 fertile controls. STL and mtDNAcn were quantified by qPCR; ROS were assessed using OxiSperm®II with semiquantitative imaging; LP was measured spectrophotometrically in seminal plasma; SCD was used to determine DNA fragmentation; and mitochondrial function was evaluated by oxygen consumption and RCR. Correlations between biomarkers and semen parameters were analysed using Pearson or Spearman coefficients, and intergroup comparisons were adjusted for age.
Semen parameters did not differ significantly between male partners of fertile and infertile couples. compared to men of fertile couples, men of infertile couples exhibited significantly shorter STL (0.57 ± 0.59 vs 1.21 ± 1.13, p_adj = 0.001) and higher oxidative stress, with both ROS (8300.9 ± 4214.8 vs 6555.3 ± 3394.3, p_adj = 0.027) and LP (88.33 ± 55.50 vs 40.29 ± 46.98, p_adj < 0.001) markedly elevated. mtDNAcn, SCD, and RCR showed no difference between the groups. Across the entire cohort, STL correlated negatively with ROS and LP and positively with RCR. ROS correlated negatively with total sperm count, motility and RCR, and positively with LP. LP displayed the strongest pattern of associations, correlating negatively with concentration, total count, motility, STL and RCR, and positively with age and volume.
Among men with normal semen analysis, partners of couples with idiopathic infertility exhibit a distinct sperm molecular profile characterised by telomere shortening and oxidative imbalance. STL, ROS and LP emerged as age-independent biomarkers associated with infertility status and showed promising discriminatory ability in this cohort, supporting their integration as second-level tests to complement routine semen analysis in cases of normozoospermia.
Ponce MR et al., 2026·Andrology·Free full text on PubMed Central
Transgender individuals assigned male at birth (AMAB) may choose to preserve their fertility prior to starting gender-affirming hormone therapy (GAHT). However, limited data exist regarding the baseline reproductive and hormonal characteristics of this population before and after GAHT.
To characterize semen quality and hormonal profiles in transgender AMAB individuals prior to GAHT and compare findings with cisgender men and with transgender individuals who discontinued GAHT for at least 3 months.
This retrospective study included transgender AMAB individuals from two tertiary andrology centers who underwent sperm cryopreservation before GAHT initiation (treatment-naïve group). Clinical evaluation included anthropometric measures, testicular volume assessment, varicocele detection, and sex hormone measures. Semen parameters were analyzed according to WHO criteria and compared with those of cisgender men and previously treated transgender individuals.
Thirty-two treatment-naïve transgender AMAB individuals were included. Hormonal parameters were generally within reference ranges. Only 46.9% of treatment-naïve individuals met WHO criteria for normozoospermia, compared with 75.5% of cisgender controls. Compared with nine previously treated individuals, estradiol levels were higher and seminal volume lower. A higher frequency of seminal abnormalities was observed, although not statistically significant.
A substantial proportion of treatment-naïve transgender AMAB individuals exhibited impaired semen parameters prior to GAHT initiation. Prior GAHT exposure showed a trend toward poorer semen quality. These findings support early fertility counseling and preservation in transgender individuals prior to GAHT initiation.
Delbarba A et al., 2026·Reviews in endocrine & metabolic disorders·Free full text on PubMed Central
Male hypogonadism is associated with significant alterations in body composition, including reduced lean body mass (LBM), increased fat body mass (FBM), particularly visceral adiposity, and impaired muscle function, contributing to frailty and cardiometabolic risk. These changes reflect the disruption of a complex endocrine crosstalk among bone, muscle, and adipose tissue, mediated by cytokines such as osteokines, myokines, and adipokines. This dysregulation promotes the development of osteosarcopenic obesity, a condition characterized by the coexistence of low bone mass, sarcopenia, and excess adiposity. Testosterone (T) plays a central role in maintaining body composition by stimulating muscle protein synthesis, inhibiting adipogenesis, and preserving bone health. Its deficiency, irrespective of etiology, leads to rapid impairment of anabolic pathways, resulting in decreased lean mass and increased fat accumulation. Evidence from clinical and experimental models demonstrates that these alterations are partially reversible with T replacement therapy (TRT), although variability exists depending on the underlying cause of hypogonadism. Dual-energy X-ray absorptiometry (DXA) represents the gold standard for assessing bone mineral density (BMD) and a key tool for evaluating body composition through a three-compartment model. It allows precise quantification of fat and lean mass, as well as their regional distribution, with minimal radiation exposure. In this review, we provide a comprehensive and clinically oriented overview of body composition alterations in male hypogonadism, focusing on underlying pathophysiological mechanisms and the practical application of DXA across different clinical scenarios. We discuss evidence from conditions such as Klinefelter syndrome, Kallmann syndrome, androgen deprivation therapy, HIV infection, and transgender care, aiming to offer a pragmatic framework for integrating body composition assessment into routine practice and improving patient management.
To evaluate the effects of treatment with FSH on seminal parameters and spontaneous pregnancy in male infertility.
Prospective, controlled, randomized clinical study.
Infertility center at a university hospital.
PATIENT(S): One hundred twelve men affected by idiopathic oligozoospermia.
INTERVENTION(S): Patients were randomized into two groups: 62 subjects were treated with 100 IU of recombinant human FSH on alternate days for 3 months, and 50 patients did not receive any treatment. Semen analysis was performed in all subjects at the end of this period of treatment and after the following 3 months. Subjects who had not reached spontaneous pregnancy underwent assisted reproductive techniques.
MAIN OUTCOME MEASURE(S): Seminal parameters, testicular cytologic analysis, FSH, LH, T, and inhibin B concentrations.
RESULT(S): The treatment group considered as a whole did not show modifications in sperm parameters. However, a subgroup of these (30, 48.4%) had a significant increase of sperm count (responder group). In the period including 3 months after the withdrawal of FSH therapy, we observed a significantly higher spontaneous pregnancy rate in the responder group (5 of 30 [16.7%]) with respect to nonresponder and nontreated groups (1 of 32 [3.1%] and 2 of 50 [4.0%], respectively). Furthermore, the improvement of seminal parameters in the responder group allowed these patients to undergo less frequent IVF-ET/intracytoplasmic sperm injection.
CONCLUSION(S): Results from this controlled, randomized clinical trial show that FSH therapy does not improve sperm concentration or pregnancy rate when infertile male patients are chosen solely by the clinical criteria of idiopathic oligospermia and normal FSH concentration. Subgroup analysis, however, does indicate that patients without maturation arrest in addition to the clinical scenario do benefit from medical therapy.
Graziani A et al., 2026·Andrology·Free full text on PubMed Central
Male factor infertility (MFI) is involved in half of the cases of couple infertility. The follicle-stimulating hormone (FSH) therapy is considered efficient to improve semen parameters and pregnancy rate in patients with idiopathic MFI, following the lesson learned from hypogonadotropic hypogonadism. However, while in patients with hypogonadotropic hypogonadism FSH therapy, in combination with human chorionic gonadotropin (hCG), is a well-established treatment, in patients with MFI the effects of the FSH therapy are variable and unpredictable. The FSH therapy in MFI should be a personalized treatment, tailored on the characteristics of the male patient and the couple. The pivotal aspect is the accurate identification of patients who might benefit from such treatment (responders) from those who might not (nonresponders). To date, selection of patients to be treated is based on history, physical examination, semen analysis, and hormonal assessment. However, these parameters cannot adequately identify a priori responder patients. Furthermore, tailored management should include pharmacological adaptation (dosage and duration of the therapy), as happens during ovarian hyperstimulation in assisted reproductive technologies. In a fully personalized therapy, pharmacogenetic factors must be considered. In this paper, we describe the evidence dealing with the pharmacogenetics of the FSH therapy in MFI, presenting the physiological and physiopathological basis and the pharmacogenetics studies dealing with effects of polymorphisms in the beta-subunit of FSH (FSHB) and the FSH receptor (FSHR) gene. According to the evidence so far available, genetic evaluation of FSHB and FSHR is recommended only for research purposes, since the data are not conclusive and even contrasting. Furthermore, the evidence so far is derived from quite small studies with different endpoints considered and relatively few cases. Better studies that consider the combined effect of several FSHB and FSHR gene polymorphisms, together with clinical, biochemical, seminal and testicular cytology, are necessary to develop an algorithm that might predict the response to the FSH treatment.
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.
Santi D et al., 2025·Journal of endocrinological investigation
Follicle-stimulating hormone (FSH) therapy improves spermatogenesis, sperm quality, and reproductive outcomes. However, variability in patients' response and limited data on pregnancy rate complicate its extensive application in male idiopathic infertility. The aim of the study was to identify predictors of FSH efficacy in male idiopathic infertility in terms of pregnancy.
A retrospective, observational study was conducted at two Italian clinics from 2019 to 2024, enrolling men with idiopathic infertility, serum FSH < 8 IU/L, treated with FSH. Data were collected at baseline (V0) and at the final follow-up visit (V1) when FSH treatment was discontinued. Different, putative "testicular indexes" (TI) were calculated. Pregnancy rate was defined at ultrasound confirmation of fetus heartbeat.
A total of 84 achieved pregnancy (19%) on 443 patients were recorded. One TI ((FSH + Total testosterone)/bi-testicular volume) was directly related to V0-semen parameters. Significant improvements in sperm concentration (p < 0.001), count (p < 0.001) and motility (p = 0.003) were observed following FSH treatment regardless of pregnancy achievement. Men who achieved pregnancy had lower baseline TI (p = 0.001), larger testicular volume (p = 0.001), and lower FSH concentrations (p = 0.001). Multivariate analysis identified patients' age (B=-0.14, standard error (SE) = 0.05, p = 0.014) and TI (B=-1.51, SE = 0.62, p = 0.015) as significant predictors of pregnancy success.
This real-life study identified a novel TI that predicts response to exogenous FSH stimulation. TI assesses the interstitial compartment function (indicated by testosterone concentrations), spermatogenic potential (FSH concentrations), and target tissue amount (testicular volume). Low baseline TI correlates with a higher likelihood of achieving pregnancy through exogenous FSH stimulation.
Male Fertility › Male Factor Treatment › Medical Management · Therapeutics › Hormonal Agents › Gonadotropins
Raffaele Scafa
R Scafa
PMID 39202711 39202711 DOI 10.3390/life14080969 10.3390/life14080969 Grande et al. 2024, Grande 2024
00240q980