title: Is oocyte meiotic spindle morphology associated with embryo ploidy? A prospective cohort study.
abstract: OBJECTIVE
  To explore whether an association exists between oocyte meiotic spindle morphology visualized by polarized light microscopy at the time of intracytoplasmic sperm injection and the ploidy of the resulting embryo.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Private IVF clinic.
  
  
  METHODS
  Patients undergoing preimplantation genetic screening/diagnosis (n = 113 patients).
  
  
  METHODS
  Oocyte meiotic spindles were assessed by polarized light microscopy and classified at the time of intracytoplasmic sperm injection as normal, dysmorphic, translucent, telophase, or no visible spindle. Single blastomere biopsy was performed on day 3 of culture for analysis by array comparative genomic hybridization.
  
  
  METHODS
  Spindle morphology and embryo ploidy association was evaluated by regression methods accounting for non-independence of data.
  
  
  RESULTS
  The frequency of euploidy in embryos derived from oocytes with normal spindle morphology was significantly higher than all other spindle classifications combined (odds ratio [OR] 1.93, 95% confidence interval [CI] 1.33-2.79). Oocytes with translucent (OR 0.25, 95% CI 0.13-0.46) and no visible spindle morphology (OR 0.35, 95% CI 0.19-0.63) were significantly less likely to result in euploid embryos when compared with oocytes with normal spindle morphology. There was no significant difference between normal and dysmorphic spindle morphology (OR 0.73, 95% CI 0.49-1.08), whereas no telophase spindles resulted in euploid embryos (n = 11). Assessment of spindle morphology was found to be independently associated with embryo euploidy after controlling for embryo quality (OR 1.73, 95% CI 1.16-2.60).
  
  
  CONCLUSIONS
  Oocyte spindle morphology is associated with the resulting embryo's ploidy. Oocytes with normal spindle morphology are significantly more likely to produce euploid embryos compared with oocytes with meiotic spindles that are translucent or not visible.
authors.affiliation: School of Women's and Children's Health, University of New South Wales; IVF Australia, Sydney, New South Wales, Australia. Electronic address: liza.tilia@ivf.com.au.
authors.forename: Liza
authors.initials: L
authors.lastname: Tilia
authors.affiliation: School of Women's and Children's Health, University of New South Wales.
authors.forename: Christos
authors.initials: C
authors.lastname: Venetis
authors.affiliation: School of Women's and Children's Health, University of New South Wales; IVF Australia, Sydney, New South Wales, Australia.
authors.forename: Suha
authors.initials: S
authors.lastname: Kilani
authors.affiliation: School of Women's and Children's Health, University of New South Wales; IVF Australia, Sydney, New South Wales, Australia.
authors.forename: Simon
authors.initials: S
authors.lastname: Cooke
authors.affiliation: School of Women's and Children's Health, University of New South Wales; IVF Australia, Sydney, New South Wales, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Chapman
mesh_terms: D000328:Adult; D015331:Cohort Studies; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D006801:Humans; D009865:Oocytes / Q000502:physiology*; D011003:Ploidies; D011247:Pregnancy; D019836:Preimplantation Diagnosis / Q000379:methods; D011446:Prospective Studies; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods; D008941:Spindle Apparatus / Q000502:physiology*
keywords: Oocyte; ploidy; polarized light microscopy; preimplantation genetic diagnosis; spindle