Correlation analysis of human embryo LeY glycan antigen expression and embryo quality

This study assessed the feasibility of using LeY glycan secretion level in human embryos as a method of judging embryo quality. Embryo culture media from patients receiving in vitro fertilization-embryo transfer was collected, and quality scores of embryos were recorded. Secretions of LeY in the culture media in different development stages (from 4-cell to 10-cell), embryos in the same development stage of the same patients (8-cell/I) and embryos in the same development stage of different patients (8-cell/I) were examined by dot-blot. Embryos were divided into a hypersecretion group and hyposecretion group, based on their LeY secretion level. The embryo quality was evaluated by clinical observations, the number which developed to D3 cell stage and the number of successful embryo transplantations. LeY secretion increased as embryos developed from 4-cell to 10-cell (P<0.05); secretion of LeY of 8/I is not identical; development speed of embryos with different secretion level of LeY was also different. The number of embryos which developed to 6-cell or higher was 82.2% in the LeY hypersecretion group but only 60% in the hyposecretion group. The rate of successful transplantation was significantly higher in the hypersecretion group (71.1 vs. 40%). In conclusion, LeY glycan secretion level in human embryos is closely related to embryo quality. LeY may become a useful measure to evaluate embryo quality in the future.