Biopsy

There are three main types of invasive preimplantation genetic testing (PGT):

1. PGT-A (for aneuploidy): screens for chromosomal abnormalities like missing or extra chromosomes; often used in cases of recurrent miscarriage, advanced maternal age, or IVF failure.
2. PGT-M (for monogenic disorders): detects specific mutations linked to inherited single-gene diseases; recommended for couples at known genetic risk.
3. PGT-SR (for structural rearrangements): identifies chromosomal abnormalities such as translocations or inversions in parents with known rearrangements.

Non-invasive PGT methods are emerging, aiming to assess chromosomal abnormalities without embryo biopsy. These rely on analyzing cell-free DNA (cfDNA) from either blastocentesis or spent culture media though they still face technical challenges and are under validation for clinical use.