title: Sperm quality in New Zealand: Is the downward trend continuing?
abstract: OBJECTIVE
  To investigate whether the decline in sperm concentration in New Zealand sperm donors observed from 1987 to 2007 continued in the period 2008-2014.
  
  
  METHODS
  A retrospective study from 2008 to 2014. The first semen sample of 285 men presenting as sperm donors in Auckland and Wellington was analysed for sperm concentration, seminal fluid volume and the percentage of motile sperm. These results were compared to results from 1987 to 2007 from the same clinics.
  
  
  RESULTS
  The decline in semen volume and sperm concentration observed between 1987 and 2007 did not continue in 2008-2014. Sperm concentration decreased from 1987 until some time between 1997 and 2001, and has remained stable at an average of 62x106/ml between 2001 and 2014. Sperm motility declined significantly (8%) in the period 2008-2014, but there was no significant change over the total period studied, between 1987 and 2014.
  
  
  CONCLUSIONS
  After a decline between 1987 and sometime during 1997-2001, the sperm concentration in men presenting as donors remained unchanged between 2002 and 2014, suggesting semen quality has not changed in New Zealand men over the last decade.
authors.affiliation: Fertility Associates, Ascot Central, 7 Ellerslie Racecourse Drive, Remuera, Auckland 1051, New Zealand. mbirdsall@fertilityassociates.co.nz.
authors.forename: Mary A
authors.initials: MA
authors.lastname: Birdsall
authors.forename: John
authors.initials: J
authors.lastname: Peek
authors.forename: Sumithra
authors.initials: S
authors.lastname: Valiapan
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D009520:New Zealand; D055101:Semen Analysis / Q000639:trends*; D013076:Sperm Count / Q000639:trends; D013081:Sperm Motility; D014019:Tissue Donors