◆What is niPGT-A?

niPGT-A is the latest non-invasive testing method in preimplantation screening, providing a gentle approach to fertilized eggs (embryos) without the need for TE cell collection.

◆Features of niPGT-A

niPGT-A is non-invasive to embryos as it does not involve the collection of TE cells, allowing for chromosomal abnormality testing without damaging the embryos compared to conventional PGT-A. The specific procedure involves retrieving culture medium from blastocysts that have grown on the 6th or 7th day after fertilization, extracting and amplifying DNA from it, and analyzing it by NGS. Blastocysts are preserved frozen until test results are obtained.

◆Advantages and Disadvantages



◆Testing Method

株式会社humedit niPGT-A(ni-PGS)chart01

① Oocyte retrieval, Intracytoplasmic Sperm Injection (ICSI), Blastocyst culture: Oocytes are retrieved, ICSI is performed, and blastocyst culture is conducted to generate embryos.
② Collect culture medium.
③ DNA in the culture medium is amplified using PCR.
Next Generation Sequencing (NGS): The amplified DNA is subjected to chromosomal analysis by Next generation sequencing (NGS).

◆Test Results

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The analysis results of NGS show the number of autosomes from 1 to 22 and sex chromosomes (X chromosome, Y chromosome). The results are plotted on a graph, with a blue line indicating trisomy (three chromosomes) and a red line indicating monosomy (only one chromosome). Normally, there are two autosomes each, and if there are no chromosomal abnormalities, they are plotted in a straight line along the baseline.
As an example, in the above test result, there is one less chromosome 16, which is expected to have a positive effect on implantation rates by excluding candidates for transplantation.
Result Example: Monosomy16, [45,XX,-16]

◆Points to Note

As of 2023, there is ongoing worldwide debate regarding the consistency of multiples between ICM biopsy or TE biopsy and the corresponding SCM of the same embryo, with no clear empirical evidence available.
Always consider false positives and false negatives.