Genetically normal embryos can decrease the risk of miscarriage and improve the safety and efficiency of your cycle; genetic testing enables us to determine which embryos are normal. Failed IVF attempts and miscarriages are often due to genetically abnormal embryos that do not continue to develop as they should. Genetic testing aids in selection of a single healthy embryo for transfer, decreasing the risk of multiple birth (and, thereby, the complications associated with it). The primary reasons people choose to move forward with PGD include:
Single Gene Disorders
Testing for single gene disorders is probably the most frequent indication for PGD. It is performed to avoid the transmission of a disorder involving a single gene from a carrier or affected parents where transmission of the gene could jeopardize the quality of life of the unborn child (e.g., cystic fibrosis, myotonic muscular dystrophy Steinert disease, Huntington’s chorea, Duchesne muscular dystrophy, etc.).
(Chromosomal Abnormalities)/PGS (Preimplantation Genetic Screening) In certain cases, testing for aneuploidy (abnormalities most frequently detected at birth, (e.g., trisomy 21, trisomy 18, Turner’s syndrome, etc.) may be indicated. In this case, the aim is to optimize the likelihood of pregnancy by selecting chromosomally normal embryos for transfer. This method could potentially be helpful in cases where couples are suspected of having a high rate of chromosomal abnormalities (advanced maternal age, recurrent miscarriages, repeat implantation failures, etc.).
What Does PGD Involve?
Because PGD is performed at the preimplantation stage, In Vitro Fertilization is required to create embryos. For technical reasons, in the case of single gene disorders, IVF with ICSI is required.
On day 3 of embryo development, when the embryo has reached the 8-cell stage, an embryo biopsy is performed by removing one cell. Genetic testing will be performed on that cell. The embryo is then returned to culture, while awaiting the results.
Usually, test results are available on day 5. Once the diagnosis for each of the embryos is received, one or more unaffected or chromosomally normal embryos are then selected for transfer.
Please note that additional fees apply.