title: Is the nuclear status of an embryo an independent factor to predict its ability to develop to term?
abstract: OBJECTIVE
  To determine the prognostic impact of the embryo nuclear status at day 2 among other major morphologic parameters (first cleavage at day 1, number of blastomeres and anuclear fragmentation at day 2) on the birth rate.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Hospital IVF department.
  
  
  METHODS
  Women undergoing 1,629 day 2 transfers of 2,732 embryos from May 2006 to November 2008.
  
  
  METHODS
  Four groups according to the embryo nuclear status.
  
  
  METHODS
  Implantation, miscarriage, and birth rates.
  
  
  RESULTS
  Univariate analysis indicated significantly higher birth rates when all blastomeres were mononucleated (15.0%) compared with embryos with not all blastomeres mononucleated (9.2%), embryos without any visible nucleus (7.7%), and embryos where at least one blastomere was multinucleated (4.2%). Multivariate analysis found significant decreased birth rates when multinucleated blastomeres were observed.
  
  
  CONCLUSIONS
  Blastomere nuclear status should be added to the kinetic and morphologic criteria traditionally used at day 2 to assess human embryo quality. The presence of multinucleated blastomeres has a negative impact on birth potential. The results argue for integrating the blastomere nuclear status at day 2 with the kinetic and morphologic criteria traditionally used to define the best embryo to transfer. Embryos with a single visible nucleus in all blastomeres should be given priority for transfer when available.
authors.affiliation: Laboratoire de Biologie de la Reproduction, Hôpital de Dijon, Université de Bourgogne, Dijon, France. patricia.fauque@chu-dijon.fr
authors.forename: Patricia
authors.initials: P
authors.lastname: Fauque
authors.forename: Etienne
authors.initials: E
authors.lastname: Audureau
authors.forename: Roger
authors.initials: R
authors.lastname: Leandri
authors.forename: Lucie
authors.initials: L
authors.lastname: Delaroche
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Assouline
authors.forename: Sylvie
authors.initials: S
authors.lastname: Epelboin
authors.forename: Pierre
authors.initials: P
authors.lastname: Jouannet
authors.forename: Catherine
authors.initials: C
authors.lastname: Patrat
mesh_terms: D000022:Abortion, Spontaneous / Q000175:diagnosis / Q000453:epidemiology; D001755:Blastocyst / Q000166:cytology* / Q000502:physiology*; D001757:Blastomeres / Q000166:cytology / Q000502:physiology; D002467:Cell Nucleus / Q000502:physiology*; D010064:Embryo Implantation; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000706:statistics & numerical data*; D006801:Humans; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011247:Pregnancy; D018873:Pregnancy Rate; D011379:Prognosis; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic / Q000706:statistics & numerical data