title: Effect of the length of time that donated embryos are frozen on pregnancy outcome.
abstract: OBJECTIVE
  To determine if the longer length of time that embryos donated to an anonymous couple have been frozen has a negative effect of subsequent successful pregnancy following thawing and transfer to the recipients.
  
  
  METHODS
  Retrospective determination of pregnancy rates according to the length of cryopreservation time has on pregnancy outcome following transfer of embryos designated for donation.
  
  
  RESULTS
  Longer time of freezing did not adversely affect subsequent pregnancy rates following frozen embryo transfer.
  
  
  CONCLUSIONS
  Donated embryos frozen for over five years (the time when some countries demand that the embryos be discarded) contributed to one-fourth of the donor embryo pool and one-third of the live deliveries.
authors.affiliation: The University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School at Camden, Cooper Hospital/University Medical Center, Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology & Infertility, Camden, NJ, USA.
authors.forename: C
authors.initials: C
authors.lastname: Wilson
authors.forename: J H
authors.initials: JH
authors.lastname: Check
authors.forename: D
authors.initials: D
authors.lastname: Summers-Chase
authors.forename: J K
authors.initials: JK
authors.lastname: Choe
authors.forename: J
authors.initials: J
authors.lastname: Amui
authors.forename: D
authors.initials: D
authors.lastname: Brasile
mesh_terms: D015925:Cryopreservation; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D018587:Oocyte Donation; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D013997:Time Factors