title: Early cleavage predicts the viability of human embryos in elective single embryo transfer procedures.
abstract: BACKGROUND
  The reduction of multiple pregnancies by using elective single embryo transfers (eSET) requires critical and careful selection of the embryo for transfer. The current study was undertaken to assess whether early cleavage could be used as a marker of embryo competence in eSET procedures.
  
  
  METHODS
  The study included analysis of 178 eSET procedures. All embryos were checked for early cleavage at 25-27 h post insemination or ICSI. The embryos that possessed two cells at 25-27 h post insemination or ICSI were designated as 'early cleavage' (EC) embryos and those that had not yet cleaved were classified as 'no early cleavage' (NEC) embryos. Selection of the embryo for transfer was based on embryo morphology and growth rate on day 2 and not early cleavage. Clinical parameters were compared between 72 EC and 106 NEC single embryo transfers.
  
  
  RESULTS
  A significantly higher clinical pregnancy rate was observed after transfer of EC (50%) than NEC (26.4%) embryos.
  
  
  CONCLUSIONS
  The current study provides compelling evidence that EC embryos possess significantly higher developmental competence than NEC embryos.
authors.affiliation: Infertility Clinic, The Family Federation of Finland, Kalevankatu 16A, FIN-00100 Helsinki, Finland. andres.salumets@vaestoliitto.fi
authors.forename: Andres
authors.initials: A
authors.lastname: Salumets
authors.forename: Christel
authors.initials: C
authors.lastname: Hydén-Granskog
authors.forename: Sirpa
authors.initials: S
authors.lastname: Mäkinen
authors.forename: Anne-Maria
authors.initials: AM
authors.lastname: Suikkari
authors.forename: Aila
authors.initials: A
authors.lastname: Tiitinen
authors.forename: Timo
authors.initials: T
authors.lastname: Tuuri
mesh_terms: D000328:Adult; D002970:Cleavage Stage, Ovum; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000033:anatomy & histology / Q000502:physiology*; D005314:Embryonic and Fetal Development; D005260:Female; D006801:Humans; D007315:Insemination, Artificial; D011247:Pregnancy; D018873:Pregnancy Rate; D011379:Prognosis; D020554:Sperm Injections, Intracytoplasmic