title: Assessment of the dominant abnormal form is useful for predicting the outcome of intracytoplasmic sperm injection in the case of severe teratozoospermia.
abstract: OBJECTIVE
  Our purpose was to investigate the relation between the dominant sperm anomaly and sperm morphology and the outcome of intracytoplasmic sperm injection (ICSI).
  
  
  METHODS
  Two hundred ninety-five patients who underwent a total of 181 cycles of in vitro fertilization (n = 168) and/or 217 cycles of ICSI (n = 177) between July 1995 and May 1997 at Keio University Hospital were investigated.
  
  
  RESULTS
  The rates of fertilization and pregnancy were 63.3 and 27.8%, respectively, in ICSI cycles with < or = 4% normal forms. When the percentage of strictly normal morphology was < or = 4, the fertilization rate was lower in the case of severely tapered head (13.0%; n = 4) than in the cases of other deformities in ICSI. The acrosomal defect made no difference in the fertilization rate with ICSI.
  
  
  CONCLUSIONS
  The predominant abnormal form affects the ICSI outcome in the case of < or = 4% normal forms.
authors.affiliation: Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Osawa
authors.forename: K
authors.initials: K
authors.lastname: Sueoka
authors.forename: S
authors.initials: S
authors.lastname: Iwata
authors.forename: M
authors.initials: M
authors.lastname: Shinohara
authors.forename: N
authors.initials: N
authors.lastname: Kobayashi
authors.forename: N
authors.initials: N
authors.lastname: Kuji
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshimura
mesh_terms: D000328:Adult; D003627:Data Interpretation, Statistical; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D008297:Male; D009845:Oligospermia / Q000473:pathology*; D009865:Oocytes; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D013094:Spermatozoa / Q000473:pathology*