Epidemiology, Etiopathogenesis, Diagnosis, and Treatment of Male Infertility — Current Trends and Future Directions: A Narrative Review

Male infertility causes 20–30% of all infertility cases globally, yet 30–40% of cases have no identified cause

Journal: Medicina (Kaunas) | Published: 2026-03-14 | Type: Narrative Review | PMID: 41901626 Authors: Wani Farooq Ahmed (Department of Pathology, College of Medicine, Jouf University, Saudi Arabia) Funding/COI: Funded by Deanship of Graduate Studies and Scientific Research at Jouf University; no COI listed

Summary

This narrative review maps what is known — and unknown — about male infertility, from epidemiology through molecular diagnostics to assisted reproduction. The central finding is that despite decades of research and expanding diagnostic tools, idiopathic male infertility (no identifiable cause) still accounts for 30–40% of cases. The review calls for molecular biomarkers, environmental exposure assessment, and stem cell approaches as future research priorities.

Claims

• Male infertility is implicated in 20–30% of all infertility cases
• Idiopathic infertility represents 30–40% of male infertility cases — the largest single diagnostic category
• Contributing factors span genetic, endocrine, structural, environmental, and lifestyle domains
• Current management includes lifestyle modification, hormonal/pharmacological therapy, surgical intervention, and ART
• Outcomes remain "suboptimal" in idiopathic and severe cases, particularly where sperm DNA fragmentation or environmental exposures are involved
• Identified research gaps: molecular/epigenetic biomarkers, environmental pollutant mechanisms, long-term ART offspring outcomes, metabolomics-guided therapy, spermatogonial stem cell therapy

Study Quality

This is a narrative review following SANRA (Scale for the Assessment of Narrative Review Articles) guidelines, which provides a loose quality framework but no systematic protocol. Literature was pulled from PubMed, Saudi Digital Library, Google Scholar, and PsycINFO — a reasonable spread, though Google Scholar inclusion introduces heterogeneous source quality. No PRISMA flow, no formal inclusion/exclusion criteria, no risk-of-bias assessment of cited studies. A single author conducted the review with no reported methodological checks.

The scope is genuinely broad — epidemiology through regenerative medicine in one paper — which means every section is necessarily superficial. Narrative reviews of this ambition are more useful as orientation documents than as evidence syntheses.

Red Flags

• Single-author narrative review: no independent screening, no dual extraction, no bias assessment
• No systematic search protocol — the literature selection is opaque
• Funded by Jouf University's own graduate research body; low conflict risk but also low independent oversight
• No conflict of interest disclosure at all, which is a gap for a medical review
• "Outcomes remain suboptimal" stated without quantifying how suboptimal — no effect sizes, no comparator data in the abstract
• Medicina (MDPI) is a legitimate journal but MDPI's rapid-publication model has a mixed peer-review reputation

Strengths

• Follows SANRA guidelines, which is better than no framework
• Covers the full pipeline from epidemiology to emerging therapies — useful as a structured overview
• Correctly identifies the 30–40% idiopathic rate as the central clinical problem, not just a footnote
• Acknowledges long-term ART offspring outcomes as an understudied area — a real gap in the literature
• Multi-database search including PsycINFO reflects awareness that psychosocial factors intersect with infertility research

Verdict

A competent orientation review that does what it promises and nothing more. It accurately maps the landscape of male infertility research and honestly names the field's biggest embarrassment — that after decades of work, the most common diagnostic category is still "we don't know." The methodology is too loose to drive clinical decisions, and the single-author, no-COI-disclosure setup warrants skepticism. Read it to get bearings on the field; don't cite it as evidence for any specific claim.