Normative values for testicular volume measured by ultrasonography in a normal population from infancy to adolescence

We obtained reference data for testicular volume measured by ultrasound in asymptomatic boys aged 0.5-18 years. In addition, we assessed the validity of the Prader orchidometer per age group by correlating it with the volume measurement by ultrasound.

The study only included healthy boys with two scrotal testes at birth and at the time of the examination. For each boy the testicular volume of both testes was measured by ultrasound and the Prader orchidometer. Testicular volumes were measured for boys aged from 1 to 18 years. The boys' ages were rounded down to the last birthday if it had occurred less than 6 months previously or rounded up to the next birthday if it was going to be within 6 months.

The volume measurement by the Prader orchidometer according to reference curves showed a statistically significant correlation. Moreover, the testicular volumes measured by the Prader orchidometer showed an accurate goodness of fit with US measurements (R(2) = 0.956).

Normative values are provided for testicular volume measured by ultrasound in boys aged 0.5-18 years. An accurate correlation was found between volume measurements by ultrasound and by the Prader orchidometer (R(2) = 0.956). Therefore, volume measurement by the Prader orchidometer, as generally used in the practice by doctors, can be used as a valid parameter for monitoring testicular growth.