Investigation into the effect of culture conditions on embryo viability and invasive and non-invasive markers of embryo selection

• Main Author: Elaimi, A. H. A.
• Published: University College London (University of London) 2014
• Subjects: 610
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.626839

The objectives of this study were to compare different culture conditions and methods used to assess preimplantation embryos. Both invasive and non-invasive markers including the blastocyst formation rate, DNA damage and aneuploidy were investigated. The first aim was to study the relationship between the metabolic profile and embryo development, morphology and aneuploidy in human embryos. The amino acid profile of 15 frozen-thawed human embryos was analysed by HPLC and the turnover of certain amino acid was significantly correlated to their developmental potential. However no relation was found between embryo morphology and its amino acid profile. The second aim was to compare murine in vitro cultured blastocysts to in vivo developed blastocysts for aneuploidy and DNA fragmentation. Two-cell stage embryos were cultured in vitro until the blastocyst stage. In vivo embryos were obtained on day 2 and day 5 following superovulation without further in vitro culture. DNA fragmentation and mosaicism increased with embryo development with higher rates for in vitro developed blastocysts compared to in vivo. The third aim was to evaluate the use of the morphokinetic parameters of EmbryoScope™ as predictors of embryo development, DNA fragmentation, aneuploidy and to assesses the effect of GM-CSF. Two-cell stage embryos were cultured until the blastocyst stage in the Embryoscope™ with and without GM-CSF. No progress in the growth rate of the GM-CSF cultured embryos was recorded. The detailed analysis of the lengths of early cleavages was informative in defining developmental potential but with no relationship with the rate of mosaicism and DNA fragmentation. The relationship between embryo viability, development, DNA fragmentation and chromosomal status is clearly complex as embryos with good morphology may reach the blastocyst stage but be chromosomally abnormal or with high DNA fragmentation. Embryo selection should be established on more than one criterion permitting the selection and transfer of one embryo with the highest implantation potential.