PGD is performed by biopsy of a blastocyst, sending some cells to the genetic laboratory and transferring the euploid embryo, i.e. an embryo with 46 chromosomes.
The patient will know the sex of the embryo and will be able to choose to transfer the embryo of the sex of her choice. PGD allows for more effective treatment and elective transfer of a single embryo.
Suggested for you: Sex Selection for Therapeutical and Non-therapeutical Purposes.