title: Failed in vitro fertilization of human oocytes: a cytogenetic analysis.
abstract: OBJECTIVE
  To investigate possible causes of in vitro fertilization (IVF) failure.
  
  
  METHODS
  A retrospective cytogenetic study of human oocytes divided into four groups or, alternatively, into two groups according to fertilization rates and whether the patients became pregnant or not. Two additional groups included oocytes in which there was no or only partial fertilization.
  
  
  METHODS
  Primary treatment of infertility in an institutional practice.
  
  
  METHODS
  Two hundred fifty-three inseminated-unfertilized oocytes from 87 women entering the IVF program because of tubal, unknown, and male infertility. Immunological infertility was excluded.
  
  
  METHODS
  Ultrasound-guided transvaginal follicular aspiration.
  
  
  METHODS
  Planned after data collection.
  
  
  RESULTS
  The rate of chromosome anomalies did not show any significant difference among the four groups established according to the fertilization rate and between pregnant and nonpregnant patients. Independently, our data identified male factor as responsible for 41%, chromosome anomalies 19.3%, oocyte immaturity 11.8%, and unknown etiology 41% of fertilization failures (based on analysis of 161 oocytes).
  
  
  CONCLUSIONS
  Fertilization rate and pregnancy outcome after IVF are not related to the incidence of oocyte chromosome anomalies.
authors.affiliation: Instituto Valenciano de Infertilidad, Valencia University School of Medicine, Spain.
authors.forename: J J
authors.initials: JJ
authors.lastname: Tarín
authors.forename: A
authors.initials: A
authors.lastname: Ruiz
authors.forename: F
authors.initials: F
authors.lastname: Miró
authors.forename: F
authors.initials: F
authors.lastname: Bonilla-Musoles
authors.forename: A
authors.initials: A
authors.lastname: Pellicer
mesh_terms: D000704:Analysis of Variance; D002869:Chromosome Aberrations; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D009865:Oocytes / Q000648:ultrastructure*; D011003:Ploidies; D011247:Pregnancy; D012189:Retrospective Studies