Preimplantation Genetic Testings (PGT) are a series of screenings that are used to genetically analyze embryos before transfer during IVF. The tests can detect early abnormalities in embryos before the uterus transfer so that only healthy embryos would be considered.
PGT-A
PGT-A, or Preimplantation Genetic Testing for Aneuploidy, screens an embryo before uterus transfer for extra or missing chromosomes. Embryos that contain too little or too much may be less likely to lead to a successful pregnancy or birth. Fetuses that are carried successfully to term with aneuploidy may be at significant risk for abnormal conditions like Down Syndrome.
PGT-M
PGT-M, or Preimplantation Genetic Testing for Single Gene/Monogenic Conditions, screens an embryo before transfer for single gene conditions. These are mainly for genetic diseases that may be hereditary or previously affected conditions. Embryos that have single gene conditions may be more likely to be at risk for a specific genetic syndrome, such as Huntington's Disease or cystic fibrosis.
PGT-SR
PGT-SR, or Preimplantation Genetic Testing for Structural Rearrangements, screens embryos for chromosomes that are present but may not be in the correct place or order. This is usually not harmful to the parent(s), but it is less likely to achieve a successful pregnancy and have a higher chance of miscarriage if an embryo has PGT-SR.
NGS
NGS, or Next Generational Sequencing, is one of the newest technologies that does extensive screenings for chromosomal conditions on new embryos during IVF. NGS can screen embryos more efficiently and accurately, greatly increasing the success rates of detecting abnormalities in the embryo before the uterus transfer.