title: The prognostic significance of day 3 embryo cleavage stage on subsequent blastocyst development in a sequential culture system.
abstract: OBJECTIVE
  To determine prognostic significance of blastomere number on Day 3 of culture upon subsequent blastocyst (BL) development.
  
  
  METHODS
  A retrospective analysis was conducted in 37 IVF subjects undergoing standard protocols and BL transfer after sequential embryo culture in P1 and BL media.
  
  
  RESULTS
  Of Day 3 embryos containing 7 or more blastomeres, 68.9% (186/270) developed into BL compared to embryos containing 4-6 blastomeres, 38.1% (56/147), P < 0.0001. The majority of BL, 68.9% (168/244), were observed on Day 5. Extended Day 6 culture represented 31.1% (76/244) of all BLs.
  
  
  CONCLUSIONS
  The observation of 7 or more blastomeres on Day 3 yielded a significantly greater likelihood of BL development. Embryos containing 4-6 blastomeres are still relatively likely to progress to a BL. Extended culture to Day 6 still yields a significant proportion of BL. Cell cleavage stage on Day 3 appears to be a useful prognostic indicator of subsequent BL development.
authors.affiliation: Department of Obstetrics and Gynecology, Women's and Children's Hospital, University of Southern California Keck School of Medicine, Los Angeles, California 90033, USA. drboostanfar@hotmail.com
authors.forename: R
authors.initials: R
authors.lastname: Boostanfar
authors.forename: J K
authors.initials: JK
authors.lastname: Jain
authors.forename: C C
authors.initials: CC
authors.lastname: Slater
authors.forename: D E
authors.initials: DE
authors.lastname: Tourgeman
authors.forename: M M
authors.initials: MM
authors.lastname: Francis
authors.forename: R J
authors.initials: RJ
authors.lastname: Paulson
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000502:physiology*; D001757:Blastomeres / Q000166:cytology / Q000502:physiology*; D004624:Embryo Transfer; D005314:Embryonic and Fetal Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D008297:Male; D018587:Oocyte Donation; D011247:Pregnancy; D011379:Prognosis; D012189:Retrospective Studies