Highlight
- Primary spermatogenic failure accounted for 56% of male infertility cases in a large prospective cohort.
- Comprehensive evaluation reduced idiopathic infertility incidence to 5.3%, significantly lower than in traditional semen-focused assessments.
- Differentiation of endocrine profiles, particularly high-FSH spermatogenic failure, underscores distinct pathophysiological mechanisms.
- Pathophysiology-based classification supports integration of hormonal and imaging markers for precision diagnosis and tailored treatment in male factor infertility.
Study Background
Male infertility (MFI) affects a significant proportion of couples experiencing reproductive challenges, contributing up to 50% of infertility cases. Traditionally, diagnosis relies heavily on semen analysis parameters, which frequently leads to the categorization of many cases as “idiopathic” when no apparent cause is identified. This label reflects a limitation in diagnostic granularity rather than true absence of pathology. Endocrine dysfunction, infections/inflammation, genetic abnormalities, and structural anomalies, which may mechanistically explain impaired spermatogenesis, are often underexplored in routine evaluation.
This clinical gap is particularly consequential because identification of specific pathophysiological subtypes has the potential to inform targeted therapeutic strategies beyond empirical treatments. Thus, moving beyond semen analysis towards a comprehensive, integrated diagnostic approach incorporating hormonal profiling, imaging, microbiology, and genetics has been advocated but lacks large-scale prospective validation.
Study Design
This was a prospective monocentric cohort study conducted at a tertiary referral academic center. The study enrolled 800 male partners of infertile couples between October 2024 and January 2026, excluding those with isolated female factor infertility. The cohort underwent a uniform, guideline-based, comprehensive evaluation protocol encompassing clinical examination, hormonal assessments (total testosterone, follicle-stimulating hormone [FSH], luteinizing hormone [LH]), scrotal ultrasonography, standardised semen analysis, microbiological investigations, transrectal ultrasound, and genetic testing.
The primary outcomes measured were the prevalence of defined male infertility pathophysiologic categories, characterization of hormonal patterns across these phenotypes, and the proportion of idiopathic infertility after exhaustive work-up.
Key Findings
The most prevalent category identified was primary spermatogenic failure, representing 56.0% of cases. This condition refers to impaired sperm production at the testicular level, frequently associated with hormonal alterations. Infection or inflammation constituted the second most common category at 22.4%, highlighting the relevance of chronic or subclinical genitourinary infections as contributors to impaired fertility.
Hypogonadotropic hypogonadism, characterized by inadequate gonadotropin stimulation leading to decreased testicular function, was observed in 8.5% of patients. Notably, only 5.3% of men remained classified as idiopathic after the extensive evaluation protocol, a marked reduction compared to historical cohorts predominantly relying on semen parameters alone.
Endocrine profiling revealed distinct hormonal signatures across infertility subtypes. High-FSH levels were predominantly associated with spermatogenic failure, reflecting a compensatory pituitary response to impaired testicular function. Conversely, hypogonadotropic hypogonadism exhibited low gonadotropin and testosterone levels indicative of hypothalamic or pituitary dysfunction.
The identified subgroups carry different prognostic and therapeutic implications. For instance, men with hypogonadotropic hypogonadism may benefit from hormonal replacement or stimulation, whereas those with infection/inflammation require targeted antimicrobial or anti-inflammatory interventions.
Expert Commentary
This study robustly confirms that male infertility is a heterogeneous condition best considered through a pathophysiological lens rather than solely by sperm parameters. The low idiopathic rate underscores the value of incorporating endocrine assessment and imaging into routine infertility work-ups, which concurs with contemporary guidelines promoting comprehensive diagnostic algorithms.
The prospective design and large, well-characterized cohort enhance the validity and generalizability of these findings. However, limitations include the single-center setting, which may influence patient demographics, and the need for cost-effectiveness analyses to justify broader implementation in diverse clinical settings.
Mechanistically, the study reinforces the role of pituitary-testicular axis evaluation in distinguishing functional spermatogenic impairments from obstructive or inflammatory causes, enabling precision medicine approaches.
Conclusion
This prospective analysis of 800 men with infertility illustrates that a pathophysiology-based classification integrating hormonal, microbiological, and imaging data significantly reduces idiopathic male infertility diagnoses and reveals clinically meaningful subgroups. These insights advance diagnostic precision and support targeted, etiology-specific treatments, potentially improving reproductive outcomes.
Future directions should include multi-center validation, longitudinal outcomes assessment, and development of standardized diagnostic pathways incorporating endocrine evaluation as a routine component of male infertility workup.
Funding and Trial Registration
Information on study funding and clinical trial registration was not specified in the source publication.
References
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5. World Health Organization. WHO Laboratory Manual for the Examination and Processing of Human Semen, 6th Edition. 2021.