Trophectoderm Biopsy Differentially Influences the Level of Serum β-Human Chorionic Gonadotropin With Different Embryonic Trophectoderm Scores in Early Pregnancy From 7847 Single-Blastocyst Transfer Cycles

To evaluate whether trophectoderm (TE) biopsy differentially influence the level of serum β-human chorionic gonadotropin (β-hCG) with different TE-scored blastocysts transferred in early pregnancy. This retrospective cohort study contained 7847 single-blastocyst transfer cycles executed between January 2019 and June 2020, including 2657 preimplantation genetic testing (PGT) cycles and 5190 fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles. All cycles were classified into biopsy and control groups, and further stratified based on the TE morphological scores into three subgroups: grades A, B, and C for TE scores, respectively. Intra-group and inter-group analyses were performed on serum β-hCG levels on the 12th day after blastocyst transfer (HCG ), and obstetric and neonatal outcomes. For cycles with a live birth, in grade A TE score subgroups, the HCG level did not exhibit statistical significance between the control and biopsy groups after adjustment (769 mIU/mL vs. 753 mIU/mL, P=0.631). In contrast, in grade B and C TE score subgroups, the control group showed a significantly higher level of HCG relative to the biopsy group (690 mIU/mL vs. 649 mIU/mL, P=0.001; 586 mIU/mL vs. 509 mIU/mL, P