title: Neonatal outcomes after the implantation of human embryos vitrified using a closed-system device.
abstract: OBJECTIVE
  Closed vitrification poses a risk of adversely affecting embryo development, while it may minimize the risk of contamination. We assessed the effects of closed-system human embryo vitrification on fetal development after implantation, neonatal outcome, and clinical safety.
  
  
  METHODS
  This was a retrospective cohort study conducted at a private fertility clinic. A total of 875 vitrified-warmed blastocysts that were single-transferred under hormone-replacement cycles between November 2011 and December 2013 were randomly divided into two groups (closed vitrification, n 313; open vitrification, n 562) after receiving the patients' consent forms. Developmental competence after implantation, including gestational age, birth weight, sex, Apgar score, and anomalies of newborns, after the transfer of blastocysts vitrified by closing vitrification was compared with that obtained in the case of open vitrification.
  
  
  RESULTS
  There were no significant differences between the use of closed and open vitrification systems in embryo development after implantation, gestational age, birth weight, sex ratio, Apgar score, and congenital anomalies of newborns.
  
  
  CONCLUSIONS
  Human embryos can be vitrified using a closed vitrification system without impairment of neonatal development.
authors.affiliation: IVF Namba Clinic, 1-17-28 Minami-horie, Nishi-ku, Osaka, 550-0015, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Iwahata
authors.forename: Shu
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Masayasu
authors.initials: M
authors.lastname: Inoue
authors.forename: Tomoko
authors.initials: T
authors.lastname: Inoue
authors.forename: Keijiro
authors.initials: K
authors.lastname: Ito
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Nakaoka
authors.forename: Nao
authors.initials: N
authors.lastname: Suzuki
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Morimoto
mesh_terms: D000328:Adult; D001724:Birth Weight / Q000502:physiology*; D001755:Blastocyst / Q000502:physiology; D010064:Embryo Implantation / Q000502:physiology; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D012189:Retrospective Studies; D058989:Vitrification