Relationship between testicular volume and testicular function: comparison of the Prader orchidometric and ultrasonographic measurements in patients with infertility

Testicular volume measured by either ultrasonography or Prader orchidometry correlated significantly with testicular function. However, critical total testicular volume indicating normal or nearly normal testicular function was 30 mL to 35 mL using Prader orchidometer and 20 mL using ultrasonography. Prader orchidometry morphometrically and functionally overestimated the testicular volume in comparison to US.