title: Delayed motherhood increases the probability of sons to be infertile.
abstract: OBJECTIVE
  To ascertain whether advanced maternal age at birth is associated with offspring infertility.
  
  
  METHODS
  A written questionnaire was completed by infertile couples attending our clinic in the presence of a researcher.
  
  
  RESULTS
  Maternal age at birth (odds ratio 1.236, 95% CI 1.100-1.388) and birth order of all respondents and their respective siblings (odds ratio 0.551, 95% CI 0.351-0.865) were significant predictors of male infertility. The probability of a man being infertile increased as mother's age at birth increased (regression coefficient +/- standard error 0.212 +/- 0.059; P < 0.001), but decreased as birth order increased (regression coefficient +/- standard error -0.596 +/- 0.230; P = 0.010).
  
  
  CONCLUSIONS
  Delayed motherhood may enhance the probability of sons to be infertile. The probability of a man being infertile would be greater if he comes from a small family than if he comes from a large family.
authors.affiliation: Department of Animal Biology, University of Valencia, Burjassot, Spain. tarinjj@uv.es
authors.forename: J J
authors.initials: JJ
authors.lastname: Tarín
authors.forename: E
authors.initials: E
authors.lastname: Vidal
authors.forename: S
authors.initials: S
authors.lastname: Pérez-Hoyos
authors.forename: A
authors.initials: A
authors.lastname: Cano
authors.forename: J
authors.initials: J
authors.lastname: Balasch
mesh_terms: D005260:Female; D006801:Humans; D007248:Infertility, Male / Q000151:congenital; D008297:Male; D008423:Maternal Age; D018566:Pregnancy, High-Risk; D012044:Regression Analysis; D012307:Risk Factors; D011795:Surveys and Questionnaires