title: Prenatal Tobacco Exposure Shortens Telomere Length in Children.
abstract: Preliminary evidence suggests a possible association between prenatal tobacco exposure and telomere length in children. This study was conducted to investigate whether maternal smoking during pregnancy was associated with telomere shortening in their children and whether prenatal and childhood exposure to environmental tobacco had any impact on this association.
  
  
  
  This is a population-representative study on the association between prenatal tobacco exposure and telomere length in children. Ninety-eight Hong Kong Chinese children aged under 15 years with prenatal tobacco exposure and 98 age- and gender-matched controls were recruited from a population health study with stratified random sampling.
  
  
  
  Telomere length in children with prenatal tobacco exposure was significantly shorter than in those with no exposure (mean T/S ratio = 24.9 [SD = 8.58] in exposed vs. 28.97 [14.15] in control groups; P = 0.02). A negative dose-response relationship was observed between the T/S ratio and tobacco exposure duration: the longer the duration of maternal smoking in pregnancy, the shorter the child's telomere length. The association between the child's telomere length and prenatal tobacco exposure remained significant after considering the influence of family socioeconomic status and exposure to environmental tobacco smoke during pregnancy and childhood.
  
  
  
  Prenatal tobacco exposure was associated with telomere shortening in children. As this may impose significant health impacts through fetal genetic programming, more efforts should be made to reduce fetal tobacco exposure by educating pregnant women to not smoke and motivating smokers to quit in early pregnancy.
  
  
  
  As reflected by telomere shortening, prenatal tobacco exposure in children can cause premature aging and increased health risks, which we suggest is entirely preventable. Not smoking during pregnancy or quitting smoking is critical to improving the health outcome of our future generations as prenatal tobacco exposure may affect children's biological programming.
authors.affiliation: Department Paediatrics and Adolescent Medicine, University of Hong Kong, Hong Kong, China; patricip@hku.hk.
authors.forename: Patrick
authors.initials: P
authors.lastname: Ip
authors.affiliation: Department Paediatrics and Adolescent Medicine, University of Hong Kong, Hong Kong, China.
authors.forename: Brian Hon Yin
authors.initials: BH
authors.lastname: Chung
authors.affiliation: Department Paediatrics and Adolescent Medicine, University of Hong Kong, Hong Kong, China.
authors.forename: Frederick Ka Wing
authors.initials: FK
authors.lastname: Ho
authors.affiliation: Department Paediatrics and Adolescent Medicine, University of Hong Kong, Hong Kong, China.
authors.forename: Godfrey Chi Fung
authors.initials: GC
authors.lastname: Chan
authors.affiliation: School of Nursing, University of Hong Kong, Hong Kong, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Deng
authors.affiliation: Department Paediatrics and Adolescent Medicine, University of Hong Kong, Hong Kong, China.
authors.forename: Wilfred Hing Sang
authors.initials: WH
authors.lastname: Wong
authors.affiliation: Department Paediatrics and Adolescent Medicine, University of Hong Kong, Hong Kong, China.
authors.forename: So Lun
authors.initials: SL
authors.lastname: Lee
authors.affiliation: Child Assessment Service, Department of Health, Government of the Hong Kong Special Administrative Region, Hong Kong, China.
authors.forename: Purdy Ying Ting
authors.initials: PY
authors.lastname: Chan
authors.affiliation: Department Paediatrics and Adolescent Medicine, University of Hong Kong, Hong Kong, China.
authors.forename: Dingge
authors.initials: D
authors.lastname: Ying
authors.affiliation: Department Paediatrics and Adolescent Medicine, University of Hong Kong, Hong Kong, China.
authors.forename: Wai Lap
authors.initials: WL
authors.lastname: Wong
authors.affiliation: Department Paediatrics and Adolescent Medicine, University of Hong Kong, Hong Kong, China.
authors.forename: Keith Tsz Suen
authors.initials: KT
authors.lastname: Tung
authors.affiliation: Department Paediatrics and Adolescent Medicine, University of Hong Kong, Hong Kong, China.
authors.forename: Yu Lung
authors.initials: YL
authors.lastname: Lau
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000235:genetics*; D012907:Smoking / Q000453:epidemiology; D012923:Social Class; D016615:Telomere; D059505:Telomere Homeostasis; D014028:Tobacco Smoke Pollution / Q000032:analysis; D055815:Young Adult
chemical_list: D014028:Tobacco Smoke Pollution