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 (Campos & Themaat, 2024) or spent culture media (Yin et al., 2021), though they still face technical challenges and are under validation for clinical use.