Non-invasive preimplantation genetic testing for aneuploidy using cell-free DNA in blastocyst culture medium

This study evaluated the performance of preimplantation genetic testing for aneuploidies (PGT-A) using cell-free DNA (cfDNA) from spent culture media (SCM) of blastocyst embryos (non-invasive PGT-A; NiPGT-A) compared with conventional trophectoderm (TE) biopsy samples.

This prospective study was conducted at IVFMD, My Duc Hospital, Vietnam, from August to December 2020, and included patients with an indication for PGT-A. The culture medium was replaced on day 3, and SCM from day 3 to the day of TE biopsy (days 5 or 6) of all biopsied blastocysts was tested using next-generation sequencing. The total concordance rate, sensitivity, and specificity of NiPGT-A versus PGT-A for detecting aneuploid embryos were calculated. Outcomes after single blastocyst transfer are also reported.

Forty-four couples participated; 100 paired TE PGT-A biopsies and SCM samples were evaluated. The whole-genome amplification success rate for SCM was 82%; 77 samples had clear NGS results and were further evaluated. The total concordance rate between NiPGT-A and PGT-A was 63.6%. For detecting aneuploidy, NiPGT-A had a sensitivity of 57.1%, specificity of 67.3%, positive predictive value of 50.0%, and negative predictive value of 73.3%. Of the 35 single euploidy embryo transfers, 8 had no NiPGT-A results, 21 were classified as NiPGT-A euploid, and 6 were classified as NiPGT-A aneuploid; the live birth rate was 51.4% (18/35). Four of the 6 NiPGT-A aneuploid blastocysts resulted in live births.

cfDNA in SCM has the potential for NiPGT-A. However, the NiPGT-A process is unreliable enough to replace traditional PGT-A using TE biopsy.