Clinical application of immunomagnetic reduction for quantitative analysis of beta-subunit of human chorionic gonadotropin in blastocyst culture media to differentiate embryo quality.

BACKGROUND: The most important factor for a successful pregnancy after in vitro fertilization is embryo quality. The aim of this study was to explore the possibility that using the immunomagnetic reduction (IMR) assay to quantitatively measure ß-subunit of human chorionic gonadotropin (ß-hCG) in blastocyst culture media to differentiate embryo quality. METHODS: This was a prospective case-control study including 28 samples of blastocyst culture media. We used single-step blastocyst culture and IMR assay to analyze ß-hCG concentrations in culture media. We also explored the relationship between IMR signals of ß-hCG and morphological grading of blastocysts. RESULTS: ß-hCG concentration-dependent IMR signals were highly correlated with blastocyst morphological quality (Spearman correlation coefficient: 0.731). Receiver-operating characteristic curve analysis showed a cut-off IMR value to differentiate embryo quality of 0.873%, with an area under the curve of 0.947, sensitivity of 0.882 and specificity of 0.818. Furthermore, subanalysis also revealed a positive correlation between ß-hCG concentration-dependent IMR signals and trophectoderm grading, with a Spearman correlation coefficient of 0.576. CONCLUSIONS: An IMR assay can quantitatively measure ß-hCG in blastocyst culture media, and may be a potential clinical tool to assist in the assessment of good blastocyst quality before embryo transfer.