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  • Print publication year: 2008
  • Online publication date: August 2010

50 - Oocyte and Embryo Freezing



Embryo cryopreservation is crucial for both the efficiency and the safety of assisted reproduction treatments. The potential risks of damage for cryopreserved-thawed embryos include exposure to medium biochemical contaminants, ice crystal formation within the embryo, toxic effect of cryoprotectants, damage during thawing process, physical damage during embryo manipulation, and DNA damage during embryo storage; but freezing itself cannot be considered a mutagenic procedure. Conventional embryo freezing concerns multicell embryos. Cryopreservation of early-stage embryos can be considered a valid alternative to conventional embryo cryopreservation. Cryopreservation of unfertilized oocytes presents more technical problems than early-stage embryo cryopreservation. The most alarming risk related with oocyte cryopreservation is aneuploidy in embryos conceived with this method. Children born from cryopreserved oocytes should be accurately monitored to ascertain the correct growth and development and to exclude possible genetic anomalies and malformations.
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