title: Sperm morphology as diagnosed by strict criteria: probing the impact of teratozoospermia on fertilization rate and pregnancy outcome in a large in vitro fertilization population.
abstract: OBJECTIVE
  To investigate the predictive value of sperm morphology assessed by strict criteria on IVF outcome.
  
  
  METHODS
  Retrospective analysis of all IVF cycles (January 1987 to December 1992).
  
  
  METHODS
  All patients were assigned to one of three groups based on sperm morphology: P-pattern (< 4% normal forms), G-pattern (4% to 14% normal forms), and N-pattern (> 14% normal forms). Morphology pattern was related to other semen characteristics and IVF outcome.
  
  
  RESULTS
  Despite corrective measures at oocyte insemination, the fertilization rate was significantly different among the three morphology groups, P < G < N. N-pattern sperm produced a mean fertilization rate over 85% regardless of low motility or concentration. In a cohort study, P-pattern cycles produced a lower implantation rate and lower ongoing pregnancy rate, independent of the lower fertilization rate.
  
  
  CONCLUSIONS
  Strict morphology is an excellent biomarker of sperm fertilizing capacity, independent of motility and concentration. P-pattern sperm may denote a poorer prognosis for establishing a pregnancy, even after a satisfactory fertilization rate is achieved.
authors.affiliation: Jones Institute for Reproductive Medicine, Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk 23507.
authors.forename: D R
authors.initials: DR
authors.lastname: Grow
authors.forename: S
authors.initials: S
authors.lastname: Oehninger
authors.forename: H J
authors.initials: HJ
authors.lastname: Seltman
authors.forename: J P
authors.initials: JP
authors.lastname: Toner
authors.forename: R J
authors.initials: RJ
authors.lastname: Swanson
authors.forename: T F
authors.initials: TF
authors.lastname: Kruger
authors.forename: S J
authors.initials: SJ
authors.lastname: Muasher
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D012044:Regression Analysis; D012189:Retrospective Studies; D013081:Sperm Motility; D013094:Spermatozoa / Q000002:abnormalities* / Q000648:ultrastructure*