Impact of trophectoderm biopsy on serum β-hCG dynamics: PGT cycles vs. non-PGT cycles.

Abstract

Purpose: Pre-implantation genetic testing (PGT), which involves trophectoderm (TE) biopsy, is commonly used to detect genetic abnormalities in embryos. However, its impact on serum β-human chorionic gonadotropin (β-hCG) levels in early pregnancy remains a topic of debate. This study evaluated the effects of TE biopsy on β-hCG dynamics. Serum β-hCG levels on days 9 and 11 post-blastocyst transfer were compared between PGT and non-PGT cycles. Additionally, β-hCG thresholds were explored as potential prognostic markers for success in assisted reproductive technology (ART).

Methods: This retrospective cohort study was conducted at the Memorial Şişli Hospital, İstanbul, Türkiye, between January 2012 and January 2021. The patients undergoing frozen-thawed single blastocyst transfer were divided into PGT (1698 cycles) and non-PGT (1830 cycles) groups. The serum β-hCG levels on days 9 and 11 after embryo transfer (ET) and the rate of β-hCG increase were compared.

Results: In both groups, higher baseline β-hCG levels and rates of increase were correlated with live birth outcomes than with clinical or biochemical pregnancy loss (p < 0.001). PGT cycles showed lower baseline β-hCG levels across all pregnancy outcomes, but no significant difference in β-hCG increase rates (p > 0.05). After adjusting for confounding factors, PGT cycles were not found to be significantly associated with β-hCG levels.

Conclusion: Serum β-hCG dynamics strongly predict live birth and clinical pregnancy. PGT did not significantly affect β-hCG levels after adjustment for confounders.