Preimpantation Diagnosis (PGD) - Preimplantation genetic screening (PGS)
Preimplantation genetic testing is a prenatal diagnosis which involves checking the genes or chromosomes of the embryos, created through IVF or ICSI, before they are implanted to the uterus. When using PGD, only healthy embryos of the desired gender are put in the uterus, giving a high accuracy rate. PGD can be used to prevent disease and for family-balancing.
Using this procedure, embryos with chromosomal aberrations and genetic diseases can be detected and excluded so that only the healthy ones will be transferred in the woman’s uterus.
PGS procedure screens for chromosomal abnormalities, such as Down Syndrome (Trisomy 21), as well as abnormalities in chromosome position (translocations). It can be recommended for parents who have no known genetic abnormalities, as well as patients who meet any of the following conditions:
- Female aged 38 or older
- Couples interested in a single embryo transfer
- Couples interested in gender selection because of gender linked diseases
- Couples with history of recurrent pregnancy loss
- Couples with history of repeated failed IVF/implantation failure
- Male partner with severe male factor infertility
PGD is used to identify single gene defects such as cystic fibrosis, Tay-Sachs disease, sickle cell anemia, β-thalasshemia and Huntington disease and generally offered in these groups of disease:
1) sex-linked disorders
2) single gene defects and
3) chromosomal disorders.
Sex selection is prohibited in Greece according to paragraph 26 of Law 3305/2005. Gender selection is only allowed for serious medical conditions and couples with a documented family history of gender-linked disease