Preimplantational Diagnosis :
This consists of detecting genetic disorders of the embryos (translocations, aneuploids, monogenic family illnesses), before their transfer to the patient’s uterus. A prior ICSI cycle is required, from which the embryos to be analysed are obtained.

On the third day of culture, a biopsy is carried out on the embryo, from which a cell is extracted in order to analyse the genetic material contained in its nucleus, while the rest of the embryo continues its development in the laboratory. The result is obtained in a few hours and gives information of the embryos that are free of genetic anomalies and, therefore, are adequate for transfer.

The PGD is indicated in the following cases:

• Couples who are carriers of chromosomal disorders or monogenic illnesses (such as cystic fibrosis, myotonic dystrophy or haemophilia).

• Repeated miscarriages.

• Failure of implantation after the ICSI cycles.

• Genetic studies of altered spermatozoids (FISH).

Photograph. Normal embryo and female - male embryos

Photograph. Abnormal embryo trisomy of chromosomes 16 and 21