title: Pregnancy after polar body biopsy and freezing and thawing of human embryos.
abstract: OBJECTIVE
  To evaluate the outcome of frozen-thawed ET using embryos previously biopsied for preimplantation genetic diagnosis during a fresh ET cycle.
  
  
  METHODS
  Prospective evaluation.
  
  
  METHODS
  Assisted reproductive biology program.
  
  
  METHODS
  A 31-year-old, G4, P1, TAB1, SAB2 carrier of a balanced RT 45,XX der(14;21)(q10;q10) translocation.
  
  
  METHODS
  Preimplantation genetic diagnosis by polar body biopsy. Excess embryos were frozen using the one-step method and then thawed.
  
  
  METHODS
  Embryo survival after thawing and subsequent pregnancy outcome.
  
  
  RESULTS
  Among the 32 mature oocytes, the results of fluorescence in situ hybridization were available for 25 polar bodies. Eleven were unbalanced, 10 were normal (8 fertilized), and 4 were balanced (3 fertilized) for the fresh IVF cycle. Two normal embryos were transferred. Four normal and 3 balanced embryos were cryopreserved. A chemical pregnancy resulted. Four months later, the 7 cryopreserved embryos were thawed; 2 survived (1 balanced and 1 normal) and were transferred. An ongoing pregnancy resulted, and a normal (46,XX) female was delivered.
  
  
  CONCLUSIONS
  Freezing and thawing of biopsied embryos resulted in a low survival rate. However, this should not be a deterrent to the cryopreservation of extra chromosomally normal embryos because the embryos that do survive are able to implant.
authors.affiliation: The New England Clinic of Reproductive Medicine, Reading, Massachusetts, USA.
authors.forename: M
authors.initials: M
authors.lastname: Lee
authors.forename: S
authors.initials: S
authors.lastname: Munné
mesh_terms: D000328:Adult; D002879:Chromosomes, Human, Pair 10; D002883:Chromosomes, Human, Pair 14; D015925:Cryopreservation; D004314:Down Syndrome; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006579:Heterozygote; D006801:Humans; D007621:Karyotyping; D009865:Oocytes / Q000502:physiology*; D011247:Pregnancy; D019836:Preimplantation Diagnosis / Q000379:methods*; D014178:Translocation, Genetic