Methods in preimplantation genetic diagnosis.

Preimplantation genetic diagnosis (PGD) is a new strategy, orientated toward primary prevention of congenital anomalies in couples with reproductive risk, such as advanced maternal age, carriers of chromosomal abnormalities, and carriers of monogenic conditions. For these patients, PGD is an acceptable alternative to prenatal diagnosis, mainly in those countries where pregnancy interruption is forbidden by law. PGD effectively avoids the implications linked to traditional prenatal diagnosis.