title: Secondary sexual characteristics and menses in young girls seen in office practice: a study from the Pediatric Research in Office Settings network.
abstract: OBJECTIVE
  To determine the current prevalence and mean ages of onset of pubertal characteristics in young girls seen in pediatric practices in the United States.
  
  
  METHODS
  A cross-sectional study was conducted by 225 clinicians in pediatric practices belonging to Pediatric Research in Office Settings, a practice-based research network. After standardized training in the assessment of pubertal maturation, practitioners rated the level of sexual maturation on girls 3 through 12 years who were undergoing complete physical examinations.
  
  
  RESULTS
  Data were analyzed for 17,077 girls, of whom 9.6% were African-American and 90.4% white. At age 3, 3% of African-American girls and 1% of white girls showed breast and/or pubic hair development, with proportions increasing to 27.2% and 6.7%, respectively, at 7 years of age. At age 8, 48.3% of African-American girls and 14.7% of white girls had begun development. At every age for each characteristic, African-American girls were more advanced than white girls. The mean ages of onset of breast development for African-American and white girls were 8.87 years (SD, 1.93) and 9.96 years (SD, 1.82), respectively; and for pubic hair development, 8.78 years (SD, 2.00) and 10.51 years (SD, 1.67), respectively. Menses occurred at 12.16 years (SD, 1.21) in African-American girls and 12.88 years (SD, 1.20) of age in white girls.
  
  
  CONCLUSIONS
  These data suggest that girls seen in a sample of pediatric practices from across the United States are developing pubertal characteristics at younger ages than currently used norms. Practitioners may need to revise their criteria for referral of girls with precocious puberty, with attention to racial differences.
authors.affiliation: Department of Maternal and Child Health, School of Public Health, University of North Carolina, Chapel Hill 27599-7580, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Herman-Giddens
authors.forename: E J
authors.initials: EJ
authors.lastname: Slora
authors.forename: R C
authors.initials: RC
authors.lastname: Wasserman
authors.forename: C J
authors.initials: CJ
authors.lastname: Bourdony
authors.forename: M V
authors.initials: MV
authors.lastname: Bhapkar
authors.forename: G G
authors.initials: GG
authors.lastname: Koch
authors.forename: C M
authors.initials: CM
authors.lastname: Hasemeier
mesh_terms: D017677:Age Distribution; D044383:Black People; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008572:Menarche / Q000208:ethnology; D015588:Observer Variation; D010372:Pediatrics; D015995:Prevalence; D011627:Puberty / Q000208:ethnology; D015203:Reproducibility of Results; D012727:Sex Characteristics; D012741:Sexual Maturation; D014481:United States; D044465:White People; D001741:Black or African American