title: Paternal age affects fertility and progeny outcome in the Brown Norway rat.
abstract: OBJECTIVE
  To investigate the effects of paternal age on fertility and progeny outcome using the Brown Norway rat model.
  
  
  METHODS
  Controlled prospective study.
  
  
  METHODS
  McIntyre Animal Centre, McGill University, Montreal, Quebec, Canada.
  
  
  METHODS
  Brown Norway male rats of increasing age were mated to young Sprague-Dawley females.
  
  
  METHODS
  Pregnancy outcome was assessed by counting the numbers of corpora lutea, resorptions, and live fetuses on day 20 of gestation. To evaluate progeny outcome, pups were examined for external malformations and weighed daily for 2 months.
  
  
  RESULTS
  There were no significant changes in the numbers of resorptions, offspring, or in the incidence of external malformations. However, there was an increase in preimplantation loss (corpora lutea minus implantation sites) in litters fathered by older males. Furthermore, a significant decrease in the average fetal weight was found with increasing paternal age. A significant increase in neonatal deaths for progeny fathered by older males also was found.
  
  
  CONCLUSIONS
  These results indicate that the quality of spermatozoa decreases as males age.
authors.affiliation: Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada.
authors.forename: V
authors.initials: V
authors.lastname: Serre
authors.forename: B
authors.initials: B
authors.lastname: Robaire
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D005314:Embryonic and Fetal Development / Q000502:physiology; D005260:Female; D005298:Fertility / Q000502:physiology*; D008297:Male; D010331:Paternal Age; D011247:Pregnancy; D011256:Pregnancy Outcome; D051381:Rats; D011914:Rats, Inbred BN; D017207:Rats, Sprague-Dawley; D013045:Species Specificity