Testicular Function and Fertility

Key Ultrasound Findings

A slightly smaller testis with normal vascularity and normal ultrasound structure does not indicate permanent infertility and should be reassuring rather than alarming, according to the European Urology guidelines 1, 2
Non-homogeneous testicular architecture, representing testicular dysgenesis and impaired spermatogenesis, is a pathological feature that suggests irreversible damage 1, 2
Testicular microcalcifications are associated with an 18-fold higher prevalence of testicular cancer and correlate with spermatogenic dysfunction, as reported by European Urology 1, 2
Severe atrophy (typically <12 mL volume) combined with structural abnormalities, such as non-homogeneous architecture or reduced blood flow, indicates irreversible testicular dysfunction 1, 3, 4

Men with unilateral cryptorchidism have paternity rates nearly equivalent to men without cryptorchidism, despite the affected testis often being smaller, according to The Journal of Urology and European Urology guidelines 1, 5
Even in bilateral cryptorchidism, where both testes may be smaller, paternity rates of 35-53% are achieved, as reported by European Urology 1
The combination of severe atrophy (<12 mL) and elevated FSH (>7.6 IU/L) indicates spermatogenic failure, according to Praxis Medical Insights and European Urology guidelines 2, 4
Abnormal ultrasound architecture (non-homogeneous, coarse, or nodular patterns) and reduced testicular blood flow on Doppler assessment are also predictive of permanent infertility 1, 2

FSH levels and testicular volume do not accurately predict spermatogenesis in all cases, as men with maturation arrest can have normal FSH and testicular volume despite severe spermatogenic dysfunction, as reported by Praxis Medical Insights 2, 6
A complete semen analysis is the definitive test to assess actual fertility status, as ultrasound findings are suggestive but not diagnostic, according to Praxis Medical Insights and European Urology guidelines 2, 6
If fertility is a concern despite reassuring ultrasound findings, obtaining two properly performed semen analyses at least one month apart, measuring serum FSH and testosterone levels, and performing a physical examination are recommended next steps, as suggested by Praxis Medical Insights and European Urology guidelines 2, 4