title: Influence of oocyte dysmorphisms on blastocyst formation and quality.
abstract: OBJECTIVE
  To identify the association between oocyte dysmorphisms and blastocyst developmental competence.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Private assisted reproduction center.
  
  
  METHODS
  This study included 5,516 embryos, which were obtained from 605 patients undergoing intracytoplasmic sperm injection cycles in which ET was performed on day 5 of embryo development.
  
  
  METHODS
  Intracytoplasmic sperm injection and ET.
  
  
  METHODS
  The morphologic characteristics of the blastocysts, namely the degree of blastocoel expansion and hatching status, the size and compactness of the inner cell mass (ICM), and the cohesiveness and number of trophectoderm cells, were correlated with oocyte dysmorphisms.
  
  
  RESULTS
  Of the 5,516 embryos evaluated, 2,920 (52.9%) reached the blastocyst stage. The blastocysts' degree of expansion and hatching status were decreased by the presence of aggregates of smooth endoplasmic reticulum clusters, large perivitelline space, and shape abnormalities. The presence of a large perivitelline space also decreased the ICM and trophectoderm cell quality. Aggregates of smooth endoplasmic reticulum clusters also decreased the ICM quality, pregnancy rate, and the miscarriage rate.
  
  
  CONCLUSIONS
  The results presented here suggest that the individual identification of oocyte dymorphisms may be a prognostic tool for blastocyst development and quality. However, the results do not diminish the importance of cleavage-stage embryo morphology assessment to predict blastocyst development competence.
authors.affiliation: Fertility, Centro de Fertilização Assistida, São Paulo, São Paulo, Brazil.
authors.forename: Daniela Paes Almeida Ferreira
authors.initials: DP
authors.lastname: Braga
authors.forename: Amanda S
authors.initials: AS
authors.lastname: Setti
authors.forename: Rita de Cássia S
authors.initials: Rde C
authors.lastname: Figueira
authors.forename: Rogério Bonassi
authors.initials: RB
authors.lastname: Machado
authors.forename: Assumpto
authors.initials: A
authors.lastname: Iaconelli
authors.forename: Edson
authors.initials: E
authors.lastname: Borges
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000502:physiology*; D016022:Case-Control Studies; D048430:Cell Shape / Q000502:physiology; D048429:Cell Size; D004624:Embryo Transfer / Q000592:standards; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D054315:Oocyte Retrieval / Q000592:standards; D009865:Oocytes / Q000166:cytology* / Q000473:pathology / Q000502:physiology; D011247:Pregnancy; D011786:Quality Control; D020554:Sperm Injections, Intracytoplasmic / Q000592:standards / Q000706:statistics & numerical data; D055815:Young Adult
keywords: Oocyte; blastocyst; oocyte shape; perivitelline space; smooth endoplasmic reticulum