title: Is sexual maturity occurring earlier among U.S. children?
abstract: OBJECTIVE
  To compare the onset and completion of sexual maturation among U.S. children between 1966 and 1994.
  
  
  METHODS
  Tanner stages were from 3042 non-Hispanic white boys, 478 black boys, 2625 white girls, and 505 black girls (NHES 1966-70), from 717 Mexican-American boys and 712 Mexican-American girls (HHANES 1982-84) and from 259 non-Hispanic white boys, 411 black boys, 291 white girls, 415 black girls, 576 Mexican-American boys and 512 Mexican-American girls (NHANES III 1988-1994). Proportions of entry into a stage, probit analysis estimated medians and selected percentiles for ages at entry were calculated using SUDAAN.
  
  
  RESULTS
  NHANES III (1988-1994) non-Hispanic white boys entered stage 2, 3, and 4 genital development and stages 3 and 4 pubic hair earlier than NHES (1966-1970) white boys, but they entered stage 5 genital development significantly later. NHANES III (1988-1994) Mexican-American boys were in stage 2, 3 and 4 genital development earlier than HHANES (1982-1984) boys, but entry into stage 5 genital and pubic hair development was not significant. NHANES III (1988-1994) white girls entered stage 5 pubic hair later than NHES (1966-1970) white girls. NHANES III (1988-1994) Mexican-American girls entered stage 2 breast and pubic hair development earlier than HHANES (1982-1984) girls, entered stage 4 breast and pubic hair development earlier but entered stage 5 pubic hair later than the HHANES (1982-1984) girls.
  
  
  CONCLUSIONS
  Persuasive evidence of a secular trend toward early maturation is not found between 1966 and 1994 in non-Hispanic black boys and non-Hispanic black and white girls. Some evidence of this trend is found in non-Hispanic white boys between 1966 and 1994 and in Mexican-American boys and girls between 1982 and 1994.
authors.affiliation: The Lifespan Health Research Center, Department of Community Health, Wright State University, School of Medicine, Dayton, Ohio, USA. shumei.sun@wright.edu
authors.forename: Shumei S
authors.initials: SS
authors.lastname: Sun
authors.forename: Christine M
authors.initials: CM
authors.lastname: Schubert
authors.forename: Rouhong
authors.initials: R
authors.lastname: Liang
authors.forename: Alex F
authors.initials: AF
authors.lastname: Roche
authors.forename: Howard E
authors.initials: HE
authors.lastname: Kulin
authors.forename: Peter A
authors.initials: PA
authors.lastname: Lee
authors.forename: John H
authors.initials: JH
authors.lastname: Himes
authors.forename: William Cameron
authors.initials: WC
authors.lastname: Chumlea
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D044383:Black People; D002648:Child; D005260:Female; D006306:Health Surveys; D006630:Hispanic or Latino; D006801:Humans; D008297:Male; D011627:Puberty; D012189:Retrospective Studies; D012737:Sex Factors; D012741:Sexual Maturation / Q000502:physiology*; D044465:White People