Page 146 - PCC02

Light
• Gametes and embryos are exposed to light at various lengths, intensities and sources both ambient and during assessment under a microscope
• Studies on mammalian pre-implantation embryos show that light can directly alter embryonic development or indirectly via photo-oxidation of components in medium(Oh 2007, Li 2014)
• Pre-compaction stage embryos can be more sensitive to direct light than post- compaction stage (Fisher 1988,Schumacher 1988). Even an hr. of visible light exposure might cause disruption for completion of meiosis and thus decrease fertilization (Hirao, 1978)
• Time lapse systems employ low energy 625-635nm red LED light of long- wavelength, combined with very short exposure times(even when images taken for several days) and thus could assist in reducing stress to the embryo(Chen 2013)
Culture of human embryos in alpha modification of Eagle’s medium under low oxygen tension and low illumination
• Implementation of an oocyte collection system employing low light at low O2% resulted in significantly increased rates of blastocyst formation of spare embryos and increased pregnancy and live birth weights when embryos were transferred on days 2-4 of culture
• Therefore it’s recommended to perform oocyte and embryo collections and manuplations under low illumination
Noda et al., F&S 1994
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