There are several couples in which one of the partners or both are carriers of a pathological gene whose expression in the fetus can lead to the onset of a serious disease. In addition, there are cases of couples who, while carrying a normal karyotype themselves, have repeated implantation failures, which may be caused by aneuploidies in the embryo.

The progress of assisted reproduction and molecular techniques now offers the possibility of diagnostic tests on the embryo from the very first stages of its development. It is one of the most important developments in the field of IVF treatment since it ensures that serious diseases can be anticipated before pregnancy begins.

The techniques used are:

• Preimplatation Genetic Diagnosis (PGD)
• Preimplatation genetic screening (PGS)