title: Effects of early cleavage patterns of human embryos on subsequent in vitro development and implantation.
abstract: OBJECTIVE
  To establish a noninvasive selection system of human embryos with a high implantation potential before transferring.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Independent IVF clinics.
  
  
  METHODS
  One hundred sixty-four patients, with 791 embryos fertilized, checked, and recorded.
  
  
  METHODS
  Embryos were divided into nine groups according to the number of cells they contained and the extent of their fragmentation during the first and second divisions. We examined the effects of the cell division pattern and division time of embryos on subsequent development in vitro and in vivo using a time-lapse incubator.
  
  
  METHODS
  Rates of blastocyst formation, high-quality blastocyst formation, and pregnancy.
  
  
  RESULTS
  The rates of embryos developed into blastocysts and blastocysts in which both the inner cell mass and trophectoderm grades were scored B or higher (good-quality blastocysts) were high in groups that formed two cells during the first division and four cells during the second division, regardless of the presence or absence of fragmentation. In these groups the first and second division times (25.90 and 37.88 hours after culture, respectively) of embryos developed into good-quality blastocysts were significantly shorter than those of other embryos. Although embryo selection based on the first and second division times did not affect the pregnancy rates after transfer at day 2 or 3 of culture, it improved the pregnancy rates after blastocyst transfer at day 5.
  
  
  CONCLUSIONS
  Transfer of blastocysts derived from embryos that completed first and second divisions within 25.90 and 37.88 hours after culture, respectively, brings about high pregnancy rates.
authors.affiliation: Aiiku Ladies Clinic, Kagoshima, Japan; Laboratory of Animal Reproduction, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan. Electronic address: lca.aiiku.lab.3f@gmail.com.
authors.forename: Yamato
authors.initials: Y
authors.lastname: Mizobe
authors.affiliation: Aiiku Ladies Clinic, Kagoshima, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Oya
authors.affiliation: Aiiku Ladies Clinic, Kagoshima, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Iwakiri
authors.affiliation: Aiiku Ladies Clinic, Kagoshima, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Yoshida
authors.affiliation: Aiiku Ladies Clinic, Kagoshima, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Laboratory of Animal Reproduction, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan.
authors.forename: Kazuchika
authors.initials: K
authors.lastname: Miyoshi
authors.affiliation: Aiiku Ladies Clinic, Kagoshima, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Tokunaga
authors.affiliation: Aiiku Ladies Clinic, Kagoshima, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ezono
mesh_terms: D001755:Blastocyst / Q000502:physiology*; D002455:Cell Division; D046149:Embryo Culture Techniques; D010064:Embryo Implantation; D004624:Embryo Transfer; D047108:Embryonic Development; D005260:Female; D005298:Fertility; D005307:Fertilization in Vitro; D006801:Humans; D007246:Infertility / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D011247:Pregnancy; D018873:Pregnancy Rate; D020554:Sperm Injections, Intracytoplasmic; D013997:Time Factors; D059008:Time-Lapse Imaging; D016896:Treatment Outcome
keywords: EmbryoScope; Embryonic division speed; first division; fragmentation; second division