Preimplantation Genetic Diagnosis (PGD)
Introduction and indications
Preimplantation Genetic Diagnosis (PGD) aims to detect chromosomal or genetic abnormalities in embryos, prior to their transfer to the woman's uterus.
The PGD technique is the result of a combination of in vitro fertilisation, biopsy of embryonic cells by micromanipulation and genetic diagnosis techniques.
PGD is indicated for the detection of severe hereditary diseases, of early onset and not susceptible to postnatal curative treatment according to current scientific knowledge, in order to carry out embryo selection of those that are not affected for transfer to the maternal uterus.
PGD is also indicated for the detection of other alterations that may compromise the viability of the embryo, such as those caused by advanced maternal age, repeated miscarriages, chromosomal alterations in the sperm and repeated implantation failure.
To obtain information about the embryo, a cell (blastomere) must be biopsied. Once extracted, the cell will be analysed for chromosomal alterations or serious genetic diseases, ruling out affected or chromosomally abnormal embryos before transfer.
In this way, only healthy embryos will be transferred, and surplus embryos can even be cryopreserved.
Embryo biopsy will not affect the future foetus, since if an embryo is damaged during the biopsy process it will stop growing and will not be suitable for transfer. The risk of damaging an embryo during biopsy is less than 0.5%.