Serum prolactin levels during puberty.

Serum prolactin (PRL) concentrations and total estrogen levels were determined in groups of boys and girls from ages eight through 15. There was no significant change in PRL concentration with advancing age in boys, and levels were comparable to adult men. In girls, mean serum PRL and estrogen levels were not significantly different from ages eight through 13 and were comparable to those found in boys of the same age groups. At age 14 and 15, an increase in PRL and estrogen levels was found in girls.