title: Duration of puberty in preterm girls.
abstract: OBJECTIVE
  Preterm birth is associated with altered pubertal timing, but the effect on pubertal duration has rarely been assessed. Here, we tested the hypothesis that preterm birth is associated with shorter duration of puberty among girls in Hong Kong where preterm birth has little social patterning.
  
  
  METHODS
  In the population-representative Chinese birth cohort "Children of 1997", we used multivariable linear regression to assess the association of preterm status (≤36 completed gestational weeks, n = 170; term birth 37-42 gestational weeks, n = 3476) with duration of puberty, adjusted for parent's highest education, mother's place of birth, maternal smoking during pregnancy, gestational diabetes, preeclampsia, and mother's age of menarche.
  
  
  RESULTS
  The mean duration from thelarche to menarche was 2.53 years. Preterm girls had a shorter duration from thelarche to menarche by 2.6 months, 95% confidence interval 0.5-4.7 months. Age of menarche did not differ by preterm status but preterm girls had later thelarche. Preterm birth was not associated with a shorter duration from pubarche to menarche.
  
  
  CONCLUSIONS
  Preterm births may be associated with shorter duration of puberty from thelarche to menarche, possibly through effects of in utero estrogen exposure, the drivers of thelarche, or the drivers of pubertal duration/progression, with potential implications for subsequent risk of cardiovascular disease and hormonal cancers.
authors.affiliation: School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: L L
authors.initials: LL
authors.lastname: Hui
authors.affiliation: Department of Paediatrics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: H S
authors.initials: HS
authors.lastname: Lam
authors.affiliation: School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: G M
authors.initials: GM
authors.lastname: Leung
authors.affiliation: School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.|CUNY School of Public Health and Hunter College, New York.
authors.forename: C M
authors.initials: CM
authors.lastname: Schooling
mesh_terms: D000293:Adolescent; D002648:Child; D015331:Cohort Studies; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D016014:Linear Models; D047928:Premature Birth / Q000453:epidemiology*; D011627:Puberty / Q000502:physiology*; D013997:Time Factors