Glycans in spent embryo culture medium are related to the implantation ability of blastocysts

Research question: Does glycan profile in spent blastocyst culture medium have the potential to be used as a biomarker to predict implantation outcome.Design: A nested case-control study was conducted in Northwest women's and children's Hospital, Xi'an, China. The patients underwent fresh IVF/ICSI cycles with single blastocyst transfer were included. Total 78 cases were included and separated into groups according to success (n = 39) and failure (n = 39) implantation outcomes. The glycosylation patterns in spent blastocyst culture medium were detected by lectin microarray containing 37 lectins using pooled samples and confirmed by reversed lectin microarray using individual sample.Results: Binding signals of 10 lectins were found to be different between samples from successful and failed implantation. And 8 of them were confirmed that glycans binding to lectin NPA, UEA-I, MAL-I, LCA and GNA were significantly increased while DBA and BPL were decreased in the successful implantation compared to failed implantation. The glycan binding to lectin PHA-E + L had no difference between two groups. No significant differences in the glycan profile were found in spent culture medium of embryos with different morphological grades except the glycan binding to UEA-I between blastocysts of Poor and blastocysts of Medium.Conclusion: Detection of glycan profile in spent culture medium may lead to a novel non-invasive assessment assay of embryo viability. In addition, these results may be helpful to further un-derstanding molecular mechanisms in embryo implantation.

Automated summary

This study investigated the potential of glycan profile in spent blastocyst culture medium as a biomarker for predicting implantation outcome. It was found that the binding signals of 10 lectins were different between successful and failed implantation samples, with increased glycan binding to lectins NPA, UEA-I, MAL-I, LCA and GNA, and decreased binding to lectins DBA and BPL in successful implantation. The glycan profile in spent culture medium showed no significant differences in embryos with different morphological grades except for the binding of UEA-I between Poor and Medium blastocysts. Therefore, detection of glycan profile in spent culture medium may provide a non-invasive assessment assay of embryo viability and contribute to understanding molecular mechanisms in embryo implantation.