title: No evidence for decreasing semen quality in four birth cohorts of 1,055 Danish men born between 1950 and 1970.
abstract: OBJECTIVE
  To compare the quality of semen in 1,055 Danish men born between 1950 and 1970 who are assumed to represent a random sample of the Danish male population of fertile age.
  
  
  METHODS
  Retrospective review of data on semen quality at the time of the female partner's first IVF treatment.
  
  
  METHODS
  The Fertility Clinic, Odense University Hospital, Odense, Denmark.
  
  
  METHODS
  One thousand fifty-five male partners of women with tubal infertility who were referred for IVF treatment consecutively during the period 1990-1996.
  
  
  METHODS
  Analysis of the semen samples delivered and used in connection with the couples' first IVF treatment.
  
  
  METHODS
  Year of birth, age at time of sample collection, sperm concentration, and semen volume.
  
  
  RESULTS
  The mean sperm concentration (+/- SD) was 183.7 x 10(6) mL and the mean semen volume (+/- SD) was 3.9 mL. A considerable variation in both parameters was found from year to year, but no significant change occurred in either parameter throughout the entire period. When four birth cohorts were compared, a later year of birth was not associated with any change in sperm concentration or semen volume.
  
  
  CONCLUSIONS
  Sperm concentration and semen volume were not related to year of birth, indicating that sperm quality has not changed in the Danish male population during the last 20-30 years.
authors.affiliation: Department of Obstetrics and Gynaecology, Odense University Hospital, Denmark.
authors.forename: P E
authors.initials: PE
authors.lastname: Rasmussen
authors.forename: K
authors.initials: K
authors.lastname: Erb
authors.forename: L G
authors.initials: LG
authors.lastname: Westergaard
authors.forename: S B
authors.initials: SB
authors.lastname: Laursen
mesh_terms: D000328:Adult; D000367:Age Factors; D003718:Denmark; D005260:Female; D006801:Humans; D007247:Infertility, Female; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012661:Semen / Q000502:physiology*; D013076:Sperm Count