title: Impact of intrauterine tobacco exposure on fetal telomere length.
abstract: OBJECTIVE
  We sought to investigate whether maternal smoking during pregnancy affects telomere length of the fetus.
  
  
  METHODS
  Pregnant women were recruited on hospital admission at delivery. A self-report questionnaire and salivary cotinine test were used to confirm tobacco exposure. Neonatal umbilical cord blood samples were collected, and genomic DNA was isolated from cord blood leukocytes and was analyzed for fetal telomere length based on quantitative polymerase chain reaction. A ratio of relative telomere length was determined by telomere repeat copy number and single copy gene copy number (T/S ratio) and used to compare the telomere length of active, passive, and nonsmokers. Bootstrap and analysis of variance statistical methods were used to evaluate the relationship between prenatal smoking status and fetal telomere length.
  
  
  RESULTS
  Of the 86 women who were included in this study, approximately 69.8% of the participants were covered by Medicaid, and 55.8% of the participants were black or Hispanic. The overall mean T/S ratio was 0.8608 ± 1.0442. We noted an inverse relationship between smoking and fetal telomere length in a dose-response pattern (T/S ratio of nonsmokers that was more than passive smokers that was more than active smokers). Telomere length was significantly different for each pairwise comparison, and the greatest difference was between active and nonsmokers.
  
  
  CONCLUSIONS
  Our results provide the first evidence to demonstrate a positive association between shortened fetal telomere length and smoking during pregnancy. Our findings suggest the possibility of early intrauterine programming for accelerated aging that is the result of tobacco exposure.
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, University of South Florida, Tampa, FL; Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, College of Medicine, University of South Florida, Tampa, FL. Electronic address: hsalihu@health.usf.edu.
authors.forename: Hamisu M
authors.initials: HM
authors.lastname: Salihu
authors.affiliation: Department of Global Health, College of Public Health, University of South Florida, Tampa, FL.
authors.forename: Anupam
authors.initials: A
authors.lastname: Pradhan
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, University of South Florida, Tampa, FL; Lawton and Rhea Chiles Center for Healthy Mothers and Babies, College of Medicine, University of South Florida, Tampa, FL.
authors.forename: Lindsey
authors.initials: L
authors.lastname: King
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, University of South Florida, Tampa, FL.
authors.forename: Arnut
authors.initials: A
authors.lastname: Paothong
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, University of South Florida, Tampa, FL; Lawton and Rhea Chiles Center for Healthy Mothers and Babies, College of Medicine, University of South Florida, Tampa, FL.
authors.forename: Chiaka
authors.initials: C
authors.lastname: Nwoga
authors.affiliation: Department of Research, USF Health, University of South Florida, Tampa, FL.
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Marty
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, College of Medicine, University of South Florida, Tampa, FL.
authors.forename: Valerie
authors.initials: V
authors.lastname: Whiteman
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003367:Cotinine / Q000032:analysis; D004247:DNA / Q000032:analysis*; D005260:Female; D005312:Fetal Blood; D005333:Fetus; D006801:Humans; D018811:Maternal Exposure; D011247:Pregnancy; D012463:Saliva / Q000737:chemistry; D012907:Smoking / Q000235:genetics*; D016615:Telomere / Q000235:genetics*; D059506:Telomere Shortening; D014028:Tobacco Smoke Pollution; D055815:Young Adult
chemical_list: D014028:Tobacco Smoke Pollution; D004247:DNA; D003367:Cotinine
keywords: bootstrapping; cotinine; fetal telomere length; tobacco exposure; umbilical cord blood