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. Plain Language Summary: To investigate the association between β-hCG and reproductive and obstetrical outcomes in women with cleavage ET and to establish different β-hCG cutoff values for the prediction of reproductive outcomes, this study retrospectively included 6909 infertile women who were divided into different groups based on the number and quality of transferred embryos, age, and transfer protocols. The cutoff values of β-hCG for predicting the presence/absence of pregnancy, biochemical pregnancy/clinical pregnancy, presence/absence of adverse pregnancy outcomes, 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 decreased significantly in the higher β-hCG groups. In conclusion, 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. [ABSTRACT FROM AUTHOR]