In the last two decades, the use of preimplantation genetic testing has 
increased dramatically. This testing is used for identifying singlegene 
disorders, chromosomal abnormalities, mitochondrial disorders, gender selection 
in non-mendelian disorders with unequal gender distribution, aneuploidy 
screening, and other preconceptually identified genetic abnormalities in 
prospective parents. Genetic testing strategies and diagnostic accuracy 
continues to improve, but not without risks or controversies. In this review the 
authors discuss the techniques and clinical application of preimplantation 
genetic diagnosis, and the debate surrounding its associated uncertainty and 
expanded use.