title: Effect of fathers' age and birth order on occurrence of congenital heart disease.
abstract: OBJECTIVE
  The aim was to examine if there is an effect of fathers' age and of birth order on the occurrence of congenital heart disease.
  
  
  METHODS
  This was a hospital based case-referent study including use of birth defects surveillance data.
  
  
  METHODS
  Subjects were 497 cases of congenital heart disease aged between 3 months and 5 years, born in Beijing and Hebei Province, China; 6222 children without congenital heart disease serve as reference baseline.
  
  
  RESULTS
  With stratified analysis and logistic regression analyses, congenital heart disease was found to be associated with fathers' age less than 25 years (odds ratio 2.63), independent of mothers' age and of birth order. There was also evidence to show a higher birth order effect on the occurrence of congenital heart disease independent of parental ages.
  
  
  CONCLUSIONS
  Higher birth order and fathers aged less than 25 years were both independently associated with some categories of congenital heart disease and with congenital heart disease overall.
authors.affiliation: Department of Epidemiology, Beijing Medical University, China.
authors.forename: S Y
authors.initials: SY
authors.lastname: Zhan
authors.forename: Z H
authors.initials: ZH
authors.lastname: Lian
authors.forename: D Z
authors.initials: DZ
authors.lastname: Zheng
authors.forename: L
authors.initials: L
authors.lastname: Gao
mesh_terms: D001722:Birth Order; D002681:China / Q000453:epidemiology; D006330:Heart Defects, Congenital / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D008297:Male; D010331:Paternal Age; D012307:Risk Factors