Preimplantation Genetic Testing, PGS can increase the success of your IVF procedure.
Preimplantation Genetic Diagnosis (PGD) and Preimplantation Genetic Screening (PGS) are genetic tests combined with the IVF process to diagnose an embryo prior to embryo transfer for an abnormal number of chromosomes or genetic mutations. Embryos that are free of genetic abnormalities can then be selected for transfer to the uterus.
The most common abnormality in embryos is called aneuploidy. Aneuploidy is when there are too many or too few chromosomes and can lead to:
- Failed pregnancy
- Termination of pregnancy
An estimated 70% of early miscarriage is associated with a chromosomal abnormality in the fetus. Some studies suggest genetic testing prior to embryo transfer helps to achieve higher implantation rates, fewer pregnancy losses and lowers the risk of having to consider pregnancy termination.
Patients who may benefit from PGS include:
- Women 35 years of age or older using their own eggs
- Women with repeated miscarriages
- Patients with multiple failed IVF cycles
- Patients who have had a previous pregnancy involving a chromosomal abnormality.
The Fertility Center of Las Vegas uses advanced PGS, which involves the removal of a few cells from a blastocyst embryo (day5 or 6). The biopsied cells are then evaluated for all 23 pairs of chromosomes. Normal embryo(s) are then selected for transfer to the patient. This procedure of biopsying the embryo at a more advanced cell stage (blastocyst) significantly increases the accuracy of the testing and minimizes potential damage that the biopsy can cause on the embryo. By waiting until the embryo reached the blastocyst stage, the embryologist will only need to remove a small portion of the embryo mass which is removed from the placental cells rather than fetal cells.
In addition to selecting chromosomal normal embryos, PGD/PGS can also identify the gender of the embryo. Gender selection can be elective or for medical reasons. Elective gender selection is made when the parents have a preference in the child’s sex and for family balancing. Medical gender selection can be beneficial for patients who have a family history of a specific sex linked disease. For example, muscular dystrophy and hemophilia are inherited by the mother but only affect male offspring. Certain other conditions impact one sex more than the other (Fragile X syndrome, autism, etc.)