title: Comparison of growth rates of fresh and frozen-thawed embryos according to chromosomal status.
abstract: OBJECTIVE
  To report a comparison of growth rates between fresh and frozen-thawed embryos on day 3 and 4 according to chromosomal status during PGD.
  
  
  METHODS
  Embryos were biopsied on day 3, fluorescent in situ hybridization performed for aneuploidy detection and growth rates monitored.
  
  
  RESULTS
  Based on 241 egg pick up-PGD and 133 frozen embryo transfer-PGD cycles. The development rate of embryos despite their chromosomal status was similar on day 3, however, overall, fresh embryos showed a significantly improved development (> or =6 cell stage; 85.7%) compared to frozen embryos (77.0%; p < 0.003). On day 4 fresh embryos showed accelerated development and further developmental improvements were associated with chromosomal normality (56.1% normal vs. 42.2% aneuploid; p < 0.004).
  
  
  CONCLUSIONS
  Cryopreservation slows embryo development regardless of the chromosomal status. However, chromosomal status did not influence the chance of embryo implantation which was the same for fresh and thawed embryos.
authors.affiliation: The Wesley IVF Service, The Wesley Hospital, Auchenflower, Brisbane, Queensland, Australia. Rohini.Edirisinghe@wesley.com.au
authors.forename: Rohini
authors.initials: R
authors.lastname: Edirisinghe
authors.forename: Rodney
authors.initials: R
authors.lastname: Jemmott
authors.forename: John
authors.initials: J
authors.lastname: Allan
mesh_terms: D015925:Cryopreservation; D020732:Cytogenetic Analysis; D010064:Embryo Implantation; D004624:Embryo Transfer; D047108:Embryonic Development; D005260:Female; D006801:Humans; D011247:Pregnancy