Can Serum β-hCG Values ​​Measured after Embryo Transfer Predict Live Birth ​​in Both Fresh and Frozen Transfers?

To determine the threshold β-hCG values ​​that can predict the live birth (LB) rates in in vitro fertilisation-embryo transfer (IVF-ET) cycles, and to compare these serum β-hCG values ​​separately in fresh and frozen embryo transfers.

Case-control study. Place and Duration of the Study: Department of Gynaecology and Obstetrics, University of Health Sciences Gulhane Training and Research Hospital, Ankara, Turkiye, between January 2017 and January 2023.

Serum β-hCG values ​​of patients who underwent single embryo transfer on Day 5 were measured on Days 12 and 14 after transfer. The patients were divided into two groups: pregnancies that resulted in live birth (LB (+)) and pregnancies that did not result in live birth (LB (-)). The two groups were compared in terms of serum β-hCG values ​​and β-hCG increase rates on the 12th and 14th days after transfer.

The median β-hCG value measured on day 12 in fresh transfers resulting in LB was found to be 277 IU/L. However, this value was found to be 332 IU/L in frozen transfers. When all transfers were considered without discrimination, it was concluded that the β-hCG test could predict LB with a sensitivity of 75% and a specificity of 72% at a value of 197 IU/L.

A cut-off value of 197 IU/L was found to be a strong parameter to predict LB in all transfers, regardless of whether the transfer was fresh or frozen. It will guide clinicians in predicting pregnancy outcomes and counselling patients.

β-hCG, Live birth, Fresh transfer, Frozen transfer, In vitro fertilisation.