Genetic compatibility is determined by testing for carriers of recessive genetic diseases. Almost all of us are carriers of recessive genetic diseases, although some of them have no clinical relevance described at present.
Carriers of these recessive genetic diseases do not manifest any symptoms as they do not develop the disease, as for the disease to develop both partners must be carriers of the same gene. Even so, these couples will have a 25% chance of having a sick child, a 25% chance of the child being healthy and a 50% chance of the children being carriers of the same gene.
This genetic compatibility test is recommended in cases of egg donation. If the donor is tested for carriers, it is recommended that the recipient couple is also tested, to rule out the possibility that the egg and sperm are carriers of the same disease. In addition, in treatments with double donation, it is also advisable to carry out genetic matching between the donors before the treatment is carried out.
In cases where both members of the couple are carriers of the same disease and wish to use their own gametes, it is advisable to carry out a Preimplantation Genetic Diagnosis (PGD) treatment to select the embryos free of the disease.