title: [Causes of male infertility. The contribution of the endocrine factor].
abstract: BACKGROUND
  Male infertility is responsible for 35% of infertile couples.
  
  
  OBJECTIVE
  To investigate the causes of male infertility and the relative importance of endocrine factors.
  
  
  METHODS
  Patients referred to an andrology clinic due to an abnormal spermiogram were studied. A testicular examination, spermiogram and determination of FSH, LH, testosterone and prolactin were done to all. Testicular biopsy was done to patients with severe oligospermia or azoospermia. Causes of infertility were defined and classified as pretesticular, testicular, posttesticular or unclassified.
  
  
  RESULTS
  Two hundred fifty seven males were studied. In 3.5% of them, the cause of infertility was defined as pretesticular (that included hypothalamic and pituitary endocrine causes), in 66.9% it was classified as testicular, in 15.6% as posttesticular and in 14%, as unclassified. Thirty percent of infertility cases were idiopathic, 17.9% were associated to varicocele, 12.8% were associated to cryptorchidism, 8.9% to Klinefelter syndrome and 6.6% to exposure to toxic substances. In 50% of patients with cryptorchidism, this abnormality was found during the specialized andrological examination and referrals for surgical correction were made late. Two thirds of patients with Klinefelter syndrome were hypoandrogenic.
  
  
  CONCLUSIONS
  Causes for male infertility should be investigated and diagnosed accurately. Primary hypoandrogenic testicular failures must be treated with hormone replacement therapy.
authors.affiliation: Departamento de Medicina, Hospital Clínico San Borja Arriarán, Facultad de Medicina, Campus Centro, Universidad de Chile.
authors.forename: E
authors.initials: E
authors.lastname: Devoto
authors.forename: M
authors.initials: M
authors.lastname: Madariaga
authors.forename: X
authors.initials: X
authors.lastname: Lioi
mesh_terms: D000293:Adolescent; D000328:Adult; D004700:Endocrine System Diseases / Q000150:complications*; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007248:Infertility, Male / Q000097:blood / Q000209:etiology*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D011388:Prolactin / Q000097:blood; D013733:Testicular Diseases / Q000150:complications; D013739:Testosterone / Q000097:blood
chemical_list: D013739:Testosterone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone