preimplantation genetic testing
Genetic analysis of embryos before transfer to identify chromosomal abnormalities or specific genetic disorders.
Full Definition
Preimplantation genetic testing (PGT) involves removing cells from an embryo for genetic analysis before transfer to the uterus. There are three types: PGT-A tests for aneuploidy (abnormal chromosome numbers), PGT-M tests for monogenic disorders (single gene defects), and PGT-SR tests for structural chromosomal rearrangements. This testing can help select embryos with the best chance of resulting in a healthy pregnancy and reduce the risk of genetic diseases. The procedure requires embryo biopsy, typically performed on day 5 or 6 blastocysts, followed by embryo freezing while awaiting results.
Usage
Usage note: Often abbreviated as PGT; older terms PGS and PGD are being phased out in favor of more specific terminology.
In Context
- "Preimplantation genetic testing revealed that 3 of 8 embryos were chromosomally normal." — Laboratory report
- "The couple opted for preimplantation genetic testing due to advanced maternal age." — Consultation note