title: Semen quality and age-specific changes: a study between two decades on 3,729 male partners of couples with normal sperm count and attending an andrology laboratory for infertility-related problems in an Indian city.
abstract: OBJECTIVE
  To compare the semen quality and age-specific changes in men between the 1980s and 2000s.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Andrology laboratory, University of Calcutta, India.
  
  
  METHODS
  A semen sample was obtained from 3729 men presenting for infertility problems in two distinct decades, that is, between 1981-85 and 2000-2006.
  
  
  METHODS
  Subjects with sperm count >20 x 10(6)/mL without any extreme pathological disorders were selected. Samples having a major liquefaction problem were excluded.
  
  
  METHODS
  A standard World Health Organization procedure for semen analysis was performed that included assessment of volume, sperm concentration, and percentage motility. The motility parameters were further classified into forward progressive motility and nonprogressive motility.
  
  
  RESULTS
  The present large-scale study confirms a significant decline in the sperm motility parameters and seminal volume in the present decade. However, no change in overall sperm concentration was noted. A decline was seen in sperm motility with increasing age in both decades.
  
  
  CONCLUSIONS
  There are significant changes in sperm motility and volume between the two decades, and the age-related changes in semen parameters are also different in the two decades.
authors.affiliation: Department of Zoology, University of Calcutta, Calcutta, India.
authors.forename: Dyutiman
authors.initials: D
authors.lastname: Mukhopadhyay
authors.forename: Alex C
authors.initials: AC
authors.lastname: Varghese
authors.forename: Manisha
authors.initials: M
authors.lastname: Pal
authors.forename: Sudip K
authors.initials: SK
authors.lastname: Banerjee
authors.forename: Asok K
authors.initials: AK
authors.lastname: Bhattacharyya
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Sharma
authors.forename: Ashok
authors.initials: A
authors.lastname: Agarwal