title: Long-term cryopreservation of human oocytes does not increase embryonic aneuploidy.
abstract: OBJECTIVE
  To determine if long-term cryopreservation of human oocytes affects oocyte developmental competence, blastocyst euploidy, or live-birth rates.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  University-based fertility center.
  
  
  METHODS
  A total of 33 patients with cryopreserved oocytes underwent oocyte thaw, blastocyst culture, trophectoderm biopsy, and 24-chromosome preimplantation genetic screening (PGS) with array comparative genomic hybridization between December 2011 and July 2014; subjects were compared with 2:1 age-matched controls with fresh oocytes whose embryos underwent trophectoderm biopsy and PGS during the same period.
  
  
  METHODS
  None.
  
  
  METHODS
  Rates of fertilization, blastulation, euploidy, implantation, and live birth.
  
  
  RESULTS
  Thirty-three patients (mean age 36.2 ± 3.8 y) thawed 475 oocytes that had been cryopreserved for a median of 3.5 years. Compared with 66 age-matched controls who underwent in vitro fertilization and PGS with fresh oocytes, embryos derived from cryopreserved oocytes demonstrated compromised blastocyst formation (54.5% vs. 66.2%) despite no impairment in fertilization (72.8% vs. 73.2%). Results showed no difference in the number of euploid blastocysts (1.7 ± 1.9 vs. 2 ± 2.5), percentage of euploid blastocysts (44.5% vs. 47.6%), rate of implantation (65% vs. 65%), or rate of live birth and ongoing pregnancy (62.5% vs. 55%) after 24-chromosome PGS with cryopreserved or fresh oocytes.
  
  
  CONCLUSIONS
  Embryos derived from cryopreserved oocytes demonstrate impaired blastulation but equivalent rates of euploidy, implantation, and live birth compared with blastocysts derived from fresh oocytes, supporting the safety and efficacy of oocyte cryopreservation.
authors.affiliation: New York University Fertility Center, New York University School of Medicine, New York, New York. Electronic address: Kara.Goldman@med.nyu.edu.
authors.forename: Kara N
authors.initials: KN
authors.lastname: Goldman
authors.affiliation: New York University Fertility Center, New York University School of Medicine, New York, New York.
authors.forename: Yael
authors.initials: Y
authors.lastname: Kramer
authors.affiliation: New York University Fertility Center, New York University School of Medicine, New York, New York.
authors.forename: Brooke
authors.initials: B
authors.lastname: Hodes-Wertz
authors.affiliation: New York University Fertility Center, New York University School of Medicine, New York, New York.
authors.forename: Nicole
authors.initials: N
authors.lastname: Noyes
authors.affiliation: New York University Fertility Center, New York University School of Medicine, New York, New York.
authors.forename: Caroline
authors.initials: C
authors.lastname: McCaffrey
authors.affiliation: New York University Fertility Center, New York University School of Medicine, New York, New York.
authors.forename: Jamie A
authors.initials: JA
authors.lastname: Grifo
mesh_terms: D000328:Adult; D000782:Aneuploidy; D016022:Case-Control Studies; D015331:Cohort Studies; D055028:Comparative Genomic Hybridization; D015925:Cryopreservation / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D009865:Oocytes; D011247:Pregnancy; D019836:Preimplantation Diagnosis / Q000706:statistics & numerical data; D013997:Time Factors
keywords: 24-chromosome preimplantation genetic screening; Oocyte cryopreservation; aneuploidy; blastocyst formation; fertility preservation