[Age of onset of spermaturia (spermache) in 669 Mexican children and its relation to secondary sexual characteristics and height].

The onset of production of spermatozoa (spermarche) indicates the beginning of reproductive capacity in men. With the purpose to establish the age of initiation of spermaturia, we performed a transversal study in 669 Mexican boys aged 9-16 years old, searching for the presence of spermatozoa in the first urine sample during five consecutive days. Besides, physical examination, including Tanner stages for genitalia and pubic hair was practiced. Spermarche (E+) occurred when the median age was 13.4 +/- 1.01 yr, the median height 155.2 +/- 8.9 cm, and the Tanner stage G2P1. The boys in Tanner stage G2P1 and E+ showed important differences in the following parameters, when they were compared with the boys in Tanner stage G2P1 and E-: height, weight, corporal surface and muscular area of the arm. The findings could be explained by the relationship between structure and function when the cellular lineages are established during different phases of development.