Concentration of hCG in Blastocoel Fluid is Independent of Embryo Morphology and PGT-A Results: Could it be a Significant Biomarker for a Competent Embryo?

The aim of this research was to develop a quantitative sandwich-strip ELISA was developed on a nitrocellulose membrane with anti-H alpha and anti-hCG beta antibodies. The detection antibody was conjugated to horseradish peroxidase, and a quantitative sandwich-strip ELISA with luminol substrate was developed following optimization with hCG. Concentration of hCG in the BF was determined for 101 embryo biopsies (Study 1) and 96 embryo biopsies (Study 2) respectively, and the results were compared with the previously recorded embryo morphology and PGT-A results. hCG was present in 73.6% of all BF specimens analysed in these two studies, and a weak correlation between hCG levels and both embryo morphology and PGT-A outcome was observed. Additionally, the receiver operating characteristic (ROC) curves show separately that both embryo morphology and PGT-A do not correlate with hCG concentrations. This indicates that the presence of hCG produced in the BF by the embryo is a separate, independent marker of embryo quality.