Pre-Implantation Genetic Diagnosis
Nowadays, it is possible to know the chromosomal and genic state of the embryos before they are implanted so that only the ‘healthy’ embryos with regard to the anomalies studied are placed in the uterus.
In general, the diseases that are usually studied include Down syndrome, Edwards syndrome, sexual chromosome alterations such as Turner syndrome and the more common monogenic diseases such as cystic fibrosis, Duchenne muscular dystrophy, etc.
A genetic study on embryos is generally recommended when the intended parents suffer from a genetic disease, which could lead to an increase in the risk of the disease appearing in their offspring.
Other reasons for which the pre-implantation diagnosis is recommended is after several miscarriages or in the case of older women, since the increase in the risk of chromosomopathies in babies when the mother is over 35 years of age is well known.
The process consists in obtaining embryos through in vitro fertilisation and, once they have reached the 6-8 cell stage, to extract one or two cells for analysis using molecular genetic techniques. Depending on the result of the study, which usually takes 1-2 days, the embryos that are found to be normal for the disease studied are transferred.
Pre-implantation genetic diagnostic: