Endocrine Abstracts

In clinical practice, the preferred method for assessing pubertal onset in boys is the orchidometer, introduced by Andrea Prader in 1966. Puberty is typically defined as beginning when the testicular size reaches 4 ml. However, several studies suggest that a testicular size of 3 ml is strongly associated with the activation of the hypothalamic-pituitary-gonadal axis and subsequent pubertal development. Recent publications indicate a secular trend toward earlier pubertal onset in girls, but data for boys are more limited. This talk will provide an overview of the physical and hormonal changes during puberty and various methods for assessing the onset and progression of puberty in boys. In addition to the orchidometer, the use of ultrasound for measuring testicular volume will be described, with examples from the Bergen Growth Study 2. The Tanner stages for genital and pubic hair development will be presented, as well as hormone measurements. Furthermore, the literature suggesting the relevance of a testicular size of 3 ml in defining the onset of puberty will be discussed. Lastly, we will address the question of whether secular changes are occurring in the age of pubertal onset in boys.