title: Oocyte zona pellucida dysmorphology is associated with diminished in-vitro fertilization success.
abstract: BACKGROUND
  Although irregularities in human zona pellucida (ZP) morphology are well described, there is scant literature on the clinical significance of ZP dysmorphology. We, therefore, designed a retrospective cohort trial of ZP dysmorphology to assess the clinical significance of ZP dysmorphology and its affect on IVF outcome. Over the same time period a random sample of 77 cycles of 77 subjects with all normal oocyte morphology were selected as controls.
  
  
  METHODS
  Between July 2006 and December 2010, all fresh non-donor cases performed at a university hospital IVF center were assessed for ZP dysmorphology. ZP dysmorphology included extracytoplasmic abnormalities (dark ZP and large perivitelline space) and oocyte shape (oval or irregularly shaped ZP). 136 IVF cycles from 119 subjects were identified where a majority of oocytes displayed ZP dysmorphology. Over the same time period a random sample of 77 cycles of 77 subjects with all normal oocyte morphology were selected as controls. IVF prognostic and outcome parameters were compared between the patients with dysmorphic and normal oocytes.
  
  
  RESULTS
  136/1710 (8.0%) cycles of fresh non-donor IVF displayed predominant ZP dysmorphology. Dysmorphic and normal oocytes showed no difference in the oocyte quality predictors such as FSH (6.03+/-2.5 vs. 6.8+/-2.3 IU/L), or AMH (2.5+/-2.0 vs. 2.30+/-1.5 ng/ml levels). ZP dysmorphology was associated with markedly diminished clinical pregnancy rates (44% vs. 70%; RR:0.62 [0.48, 0.80]; p = 0.0002), implantation rates (.17 vs. .36; IRR: 0.48 [0.34, 0.68]; p < 0.0001) and live birth rates as compared to non dysmorphic oocytes (29% vs. 52%; RR:0.55 [0.39, 0.79]; p = 0.001).
  
  
  CONCLUSIONS
  ZP dysmorphology is associated with markedly diminished pregnancy and implantation rates in IVF. The poorer outcome appears to be independent of the usual markers of ovarian reserve.
authors.forename: May-Tal
authors.initials: MT
authors.lastname: Sauerbrun-Cutler
authors.forename: Mario
authors.initials: M
authors.lastname: Vega
authors.forename: Andrzej
authors.initials: A
authors.lastname: Breborowicz
authors.forename: Eric
authors.initials: E
authors.lastname: Gonzales
authors.forename: Daniel
authors.initials: D
authors.lastname: Stein
authors.forename: Mathew
authors.initials: M
authors.lastname: Lederman
authors.forename: Martin
authors.initials: M
authors.lastname: Keltz
mesh_terms: D000328:Adult; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate; D015044:Zona Pellucida / Q000473:pathology*
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