Preimplantation Genetic Testing (PGT-A)
Preimplantation Genetic Testing for Aneuploidy (PGT-A) is an advanced reproductive technology that enables the screening of embryos for chromosomal abnormalities prior to implantation during in vitro fertilization (IVF) treatment. By identifying euploid embryos (those with the correct number of chromosomes), PGT-A aims to enhance the chances of successful implantation and reduce the risk of miscarriage.
- Purpose and Importance:
- PGT-A is utilized to assess the chromosomal integrity of embryos created through IVF, identifying those with an abnormal number of chromosomes (aneuploidy).
- Chromosomal abnormalities are a leading cause of implantation failure, miscarriage, and certain genetic disorders in offspring.
- By selecting euploid embryos for transfer, PGT-A aims to improve IVF success rates and reduce the likelihood of pregnancy complications.
- Procedure:
- Embryo Biopsy: PGT-A involves the removal of one or more cells from each embryo on day 5 or 6 of development (blastocyst stage) for genetic analysis.
- Genetic Analysis: The biopsied cells are subjected to comprehensive chromosomal screening using advanced genetic techniques, such as next-generation sequencing (NGS).
- Reporting Results: Following genetic analysis, embryos are classified as euploid (normal chromosome count), aneuploid (abnormal chromosome count), or mosaic (containing both euploid and aneuploid cells). This information helps inform embryo selection for transfer.
- Benefits of PGT-A:
- Enhanced IVF Success: By transferring only euploid embryos with the correct chromosome count, PGT-A can significantly increase the chances of successful implantation and ongoing pregnancy.
- Reduced Miscarriage Risk: Euploid embryos have a lower risk of miscarriage compared to embryos with chromosomal abnormalities, thereby improving the likelihood of achieving a healthy pregnancy.
- Family Balancing: PGT-A enables the selection of embryos based on their genetic characteristics, allowing individuals and couples to screen for specific genetic conditions or gender preferences.
- Considerations and Limitations:
- False Positives and Negatives: PGT-A may yield false-positive or false-negative results, leading to the misclassification of embryos as euploid or aneuploid. These inaccuracies can impact treatment decisions and pregnancy outcomes.
- Mosaicism: The presence of mosaic embryos, which contain a mixture of euploid and aneuploid cells, complicates embryo selection and interpretation of PGT-A results. Further research is needed to understand the implications of mosaic embryos on IVF success rates and pregnancy outcomes.
We partner with Igenomix, the leading fertility genetics lab in the United States. Click here and here to read more about how PGT-A is done at their lab and their statistics.