Noninvasive preimplantation genetic testing for aneuploidies (nipgt-a) x analysis of the whole embryo: high degree of concordance between the genetic results.

After many years of using PGT-A, there are still many concerns, such as risks of invasive action and difficulties in the correct interpretation of mosaicism, which may lead to errors in the interpretation of false-positive and false-negative results. Recently, a new technology (Noninvasive Preimplantation Genetic Testing -NIPGT-A) has arisen using cell-free DNA present in the spent culture media of human blastocysts. However, there are still few genetic analyses of concordance between NIPGT-A and the whole embryo (gold standard). The objective of this study was to analyse the degree of concordance between NIPGT-A versus genetic analysis of the whole embryo. This cohort study included a total of 56 blastocysts vitrified on Day-5 that were previously biopsied for PGT-A. All embryos had a diagnosis of aneuploidy and were donated under informed consent by patients following the Human Medical Authority regulations. Blastocysts were thawed and cultured in 15μl drops of culture medium under oil. After their expansion (4-8 hours), the blastocysts and their corresponding spent media were transferred to PCR tubes and stored at -80°C until analysis. DNA in all samples(spent culture medium and whole embryo) was amplified by MALBAC® technology (Yikon Genomics). The DNA concentration of the amplified product was measured using a Qubit 3.0 Fluorometer (Thermo Fisher Scientific). The samples were subjected to next-generation sequencing (NGS) using the Illumina MiSeq® system. The ploidy status results obtained from ChromGoTM software (Yikon Genomics) for spent culture medium and the whole embryo were compared to determine the accuracy of NIPGT-A for screening chromosomal abnormalities in each embryo. DNA from all 56 spent medium samples and whole embryos were successfully amplified. Comparing the results of NIPGT-A and whole-embryo sequencing (Table 1), the positive predictive value (PPV) was 93.5%, and the false-positive rate (FPR) was 6.5%. Agreement analysis showed very good coefficient concordance (Cohen's Kappa coefficient: 0.84).Tabled 1Table 1. NIPGT-A X Whole Embryo: resultsNIPGT-AWhole EmbryoAneuploidEuploidTotalAneuploid43346Euploid01010Total431356PPV:93.5% FPR:6.5%Kappa: 0.84 Open table in a new tab PPV:93.5% FPR:6.5% Kappa: 0.84 Cell free DNA ploidy evaluated by NIPGT-A presents very good concordance that of the DNA from whole embryo cells (Cohen's Kappa concordance coefficient: 0.84).