Mini review shows that a testicular volume of 3 mL was the most reliable clinical sign of pubertal onset in males

Abstract

Aim: We aimed to evaluate aspects of pubertal development to identify the most reliable clinical sign of pubertal onset in males. Methods: We performed a mini review of the literature. Results: In 1951 Reynolds and Wines categorised pubic hair growth and genital development in five stages by visual inspection. Today the Tanner scale is used to assess the five stages of pubertal development, The second genital stage, characterised by enlargement of the scrotum defines pubertal onset in males. Testicular volume may be evaluated by using a calliper or by ultrasound scan. The Prader orchidometer, described in 1966, offers a method for evaluating testicular growth by palpation. Pubertal onset is commonly defined as testicular volume >3 or ≥4 mL. The development of sensitive laboratory methods has enabled studies analysing hormonal activity in the hypothalamus-pituitary-gonadal axis. We review the relationships between physical and hormonal signs of puberty. We also discuss the results of studies assessing different aspects of pubertal development with a focus on identifying the most reliable clinical sign of pubertal onset in males. Conclusion: A substantial amount of evidence supports testicular volume of 3 mL as the most reliable clinical sign of male pubertal onset.