Preimplantation genetic diagnosis: technological advances to improve accuracy and range of applications

Preimplantation genetic diagnosis (PGD) is an option for couples who are at risk that enables them to have unaffected progeny without facing the risk of pregnancy termination after prenatal diagnosis as currently practiced. It is also one of the practical tools used in assisted reproduction technology to improve the chance of conception for infertility cases with poor prognosis. Because PGD is performed using a single biopsied cell, technological advances are important to improving PGD accuracy. This has contributed to the avoidance of misdiagnosis in PGD for single gene disorders, and extensive experience in PGD for chromosomal disorders suggests strategies for more reliable evaluation of the chromosomal status of the preimplantation embryo. This paper describes the present status of PGD for genetic and chromosomal disorders, its accuracy and range, and how PGD is an integral part of IVF and genetic practices.