Normal Pubertal Development: Part II: Clinical Aspects of Puberty

All of the following are based on strong research evidence: • Breast development before 8.0 years of age is unusual in the general population of normal-weight girls in the United States, but breast development is normal in the seventh year in girls of minority ethnic status (non-Hispanic African American and Mexican American). • Obesity advances the onset of puberty in girls. • Pubertal development in boys is 1 to 2 years later than in girls, on average. • Missing a menstrual period for 90 or more days or having an average cycle length less than 21 days is abnormal for a girl of any age, and an average cycle length of more than 45 days by 2 years after menarche is a risk factor for ongoing oligoanovulation. • Pubertal growth and development and menstrual cyclicity are sensitive indicators of general health. 2011 © Copyright American Academy of Pediatrics. All rights reserved.