Can a Subclinical Varicocele Cause Testicular Atrophy?
Yes, subclinical varicoceles can cause testicular atrophy, but they should not be treated because treatment does not improve fertility outcomes. 1
Key Evidence from Guidelines
The 2025 European Association of Urology guidelines provide a strong recommendation stating: "Do not treat varicocele in infertile men who have normal semen analysis or in men with a subclinical varicocele." 1 This recommendation is based on evidence showing that treatment of subclinical varicoceles was not effective at increasing the chances of spontaneous pregnancy. 1
Understanding the Paradox
While subclinical varicoceles can be associated with decreased testicular volume, this does not translate into a clinically meaningful impact on fertility:
Research confirms the association: A 1997 study demonstrated that men with subclinical left varicoceles had significantly reduced left testicular volume compared to right testicular volume (13.2 versus 14.7 mL). 2 This finding parallels what occurs with clinical varicoceles.
But atrophy doesn't predict infertility: A 1994 study of 946 men found that while varicoceles cause significant ipsilateral testicular atrophy/hypotrophy, there was no correlation between loss of testicular volume and fertility status in men with left varicoceles. 3 Both fertile and infertile men with varicoceles showed similar degrees of testicular volume loss.
Treatment doesn't help: The critical point is that treating subclinical varicoceles does not improve pregnancy rates, even when testicular volume differences exist. 1, 4
Clinical Algorithm for Management
For adults with subclinical varicocele:
- Observation only, regardless of testicular size discrepancy
- No surgical intervention indicated
- Focus on other potential causes of infertility if present
For adolescents with subclinical varicocele:
- The guidelines do not recommend treatment
- Even in adolescents, surgery is only indicated for clinical varicoceles with persistent testicular size difference >2 mL or 20%, confirmed on two visits 6 months apart 1
Important Caveats
Do not confuse subclinical with clinical varicoceles: The distinction is crucial. Clinical varicoceles (palpable on examination) with abnormal semen parameters in infertile men should be treated, as this improves fertility rates. 1 Subclinical varicoceles (detected only by imaging, not palpable) should not be treated.
Avoid the trap of treating based on ultrasound findings alone: Routine ultrasonography to investigate presumed varicocele should be discouraged, as treatment of non-palpable varicoceles is not associated with improvement in either semen parameters or fertility rates. 5
The evidence is clear and consistent: while subclinical varicoceles may be associated with some degree of testicular volume loss, this finding alone does not warrant intervention because treatment does not improve the outcomes that matter—fertility, pregnancy rates, and quality of life.