title: Impact of early cleaved zygote morphology on embryo development and in vitro fertilization-embryo transfer outcome: a prospective study.
abstract: OBJECTIVE
  To evaluate the impact of the first division morphology on embryo development and IVF-embryo transfer outcome.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Teaching hospital, France.
  
  
  METHODS
  All zygotes from 201 couples were checked for early cleavage. We defined as "even," early cleaved (EC) zygotes with 2 cells of even size; as "uneven," EC zygotes with 2 cells of uneven size; and as "fragmented," EC zygotes with more than 20% fragmentation rate. Day 2 embryo quality was assessed as "top" embryo or "non-top," with the evaluation of multinucleated blastomeres.
  
  
  METHODS
  None.
  
  
  METHODS
  Day 2 embryo quality, pregnancy and implantation rates.
  
  
  RESULTS
  Among EC zygotes, 59.1% were even, 13.0% were uneven, and 27.9% were fragmented. Even EC yielded more "top" embryos and less multinucleated blastomere embryos than uneven EC (77.0% vs. 46.3%) and fragmented EC (77.0% vs. 13.9%). The 125 double embryo transfers that comprised at least one embryo derived from even EC zygote led to higher pregnancy rate (PR) (64.0% vs. 43.4%) and implantation rate (42.0% vs. 27.6%) compared to the 76 double embryo transfers with embryos derived from breakdown or 2PN zygotes.
  
  
  CONCLUSIONS
  The morphology of the early cleaved zygote is involved in embryo development. Evaluation of this morphology is an effective and valuable method of assessing the embryo quality.
authors: APHP, Departments of Biology and Genetics of Reproduction, Antoine Béclère Hospital, Clamart, France. laetitia.hesters@abc.aphp.fr
authors: Laëtitia
authors: L
authors: Hesters
authors: Nadia
authors: N
authors: Prisant
authors: Renato
authors: R
authors: Fanchin
authors: Daniel H
authors: DH
authors: Méndez Lozano
authors: Estelle
authors: E
authors: Feyereisen
authors: René
authors: R
authors: Frydman
authors: Gérard
authors: G
authors: Tachdjian
authors: Nelly
authors: N
authors: Frydman
mesh_terms: D000328:Adult; D002455:Cell Division; D003470:Culture Media; D004624:Embryo Transfer; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D006801:Humans; D010062:Ovulation Induction / Q000379:methods; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D011446:Prospective Studies; D015053:Zygote / Q000166:cytology* / Q000502:physiology
chemical_list: D003470:Culture Media