Validation of non-invasive preimplantation genetic testing for aneuploidies (niPGT-A) in a Japanese population: experience from seven clinics.

Purpose: The aim of this study was to determine the feasibility of implementing non-invasive PGT-A (niPGT-A) in clinical practice. Informativity and concordance rates between three sample types (embryonic cell-free DNA [cfDNA] present in spent blastocyst medium [SBM], trophectoderm [TE] biopsy, and whole blastocyst [WB]) from the same embryo were evaluated.

Methods: This was a prospective, multicenter study conducted between February 2022 and November 2022 at seven Japanese IVF centres. 212 blastocysts were donated for research. The cfDNA released into the SBM was analysed, and the results were compared against the corresponding TE biopsy and WB sample.

Results: Overall informativity rates for SBM, TE, and WB were 81.6% (173/212), 98.6% (209/212), and 98.6% (209/212), respectively. There was no difference between TE and WB; however, SBM was significantly different to both (p < 0.001). The informativity rate in SBM samples significantly varied among the seven centres, ranging between 72.7 and 97.1% (p = 0.041). Ploidy concordance (SBM-TE) also varied across the centres, ranging between 68.2 and 90.9%; however, this did not reach statistical significance (p = 0.63). Ploidy concordance rates in SBM-TE, SBM-WB, and TE-WB were 77.4% (130/168), 77.4% (130/168), and 90.5% (152/168), respectively. There was no statistical difference for SBM-TE and SBM-WB, but both were statistically different to TE-WB (p = 0.0054).

Conclusion: We have shown results that are consistent with the existing literature, indicating the feasibility of applying the niPGT-A protocol described here, and thus using the SBM result to establish a priority for embryo transfer.

Trial registration information: The study was approved by Tokushima University Hospital Life Science and Medical Research Ethics Review Committee (Permission number: 4057).