title: The influence of varicocele on parameters of fertility in a large group of men presenting to infertility clinics. World Health Organization.
abstract: OBJECTIVE
  To assess the role of varicocele in male infertility.
  
  
  METHODS
  Data analysis of a large population of couples who were systematically investigated for infertility.
  
  
  METHODS
  Couples were recruited in 34 World Health Organization collaborating centers in 24 countries.
  
  
  METHODS
  Nine thousand thirty-four men presenting as partner of infertile couples.
  
  
  METHODS
  None.
  
  
  METHODS
  Physical findings, semen characteristics, coincidental pathology, and spontaneous pregnancies.
  
  
  RESULTS
  Varicocele was found in 25.4% of men with abnormal semen, compared with 11.7% of men with normal semen. It was accompanied by decreased testicular volume, impaired sperm quality, and decline of Leydig cell secretion. Spontaneous pregnancies were as frequent in couples in whom the men did or did not have varicocele.
  
  
  CONCLUSIONS
  Varicocele is clearly associated with impairment of testicular function and infertility.
mesh_terms: D005260:Female; D005298:Fertility; D006801:Humans; D015994:Incidence; D007248:Infertility, Male / Q000209:etiology*; D008297:Male; D011247:Pregnancy; D012661:Semen / Q000502:physiology; D013737:Testis / Q000473:pathology; D014646:Varicocele / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology