title: Should we forget about embryos till day 5?
abstract: OBJECTIVE
  To find the way of having more and better blastocyst is essential. How to culture embryos up to blastocyst stage remains critical.
  
  
  RESULTS
  Several studies show how a blastocyst score can predict the implantation potential. If that score is enough to choose the best blastocyst, as culture conditions would not be affected in these days, we would not need to check early cleavage embryos, even it could be better for the embryo development.
  
  
  CONCLUSIONS
  The item that should be discussed is if it is better to evaluate or not embryos at early cleavage stages. If we do not check embryos on days 2 and 3, we should change our way to work and how to culture those embryos. First step would be to perform all embryo transfers on day 5 or 6. If we let embryos grow to blastocyst without any morphology evaluation, we should adapt several steps in our laboratory, for example we should move to a single-step culture medium or we should not do assisted hatching on day 3 embryos.
authors.affiliation: IVI Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Bronet
authors.forename: David
authors.initials: D
authors.lastname: Agudo
mesh_terms: D001755:Blastocyst / Q000502:physiology*; D002970:Cleavage Stage, Ovum / Q000502:physiology; D003470:Culture Media; D004624:Embryo Transfer; D047108:Embryonic Development / Q000502:physiology; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate
chemical_list: D003470:Culture Media