Puberty: When is it normal?

C lassically, the normal chronological age for pubertal onset is between 8 and 13 years in girls and 9 and 14 years in boys based on data from epidemiological studies from the 60's (1). However, the age limit for pubertal timing is still a challenge (2,3). It is well known that puberty is a complex and multi factorial process that involves genetic, metabolic, socio economic, nutritional and ethnic factors. Moreover, the evidence that initial pubertal signs, mainly in girls, are appearing earlier today than in the last 4 decades has been described by several epidemiological studies (2-4).