Diagnostic value of a single β-hCG test in predicting reproductive outcomes in women undergoing cleavage embryo transfer: a retrospective analysis from a single center

PURPOSE: The present study investigated the role of β-hCG in predicting reproductive outcomes and established optimal β-hCG cutoff values in women undergoing cleavage embryo transfer. METHODS: The patients were transferred with fresh or frozen-thawed embryos and had serum β-hCG levels tested on the 14th day post-embryo transfer. Serum β-hCG levels were compared between different groups. Different cutoff values of β-hCG were established and used to divide the patients into different groups. Reproductive outcomes between groups based on β-hCG levels were compared. RESULTS: Significant discrepancies in general characteristics were observed in the subgroups. The cutoff values of β-hCG for predicting the presence/absence of pregnancy, biochemical pregnancy/clinical pregnancy, presence/absence of adverse pregnancy outcomes, and singleton/twin live birth in the cleavage groups were 89.6, 241.1, 585.9, and 981.1 mIU/L, respectively. Biochemical pregnancy rates and adverse pregnancy outcome rates significantly decreased from the low β-hCG group to the higher β-hCG group in sequence. Significantly higher full-term live birth rates were observed in the highest β-hCG group (P < 0.001). CONCLUSION: Serum β-hCG levels were strongly associated with reproductive outcomes. However, the interpretation of β-hCG levels must consider the number and quality of embryos and transfer protocols. When β-hCG was tested on a fixed day post-ET, different cutoff values were required for the prediction of early clinical outcomes. The association between β-hCG and obstetric outcomes must be investigated. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12978-022-01455-1.