The use of preimplantation genetic diagnosis (PGD) to screen embryos for 
aneuploidy and genetic disease is growing. New uses of PGD have been reported in 
the past year for screening embryos for susceptibility to cancer, for late-onset 
diseases, for HLA-matching for existing children, and for gender. These 
extensions have raised questions about their ethical acceptability and the 
adequacy of regulatory structures to review new uses. This article describes 
current and likely future uses of PGD, and then analyses the ethical issues 
posed by new uses of PGD to screen embryos for susceptibility and late-onset 
conditions, for HLA-matching for tissue donation to an existing child, and for 
gender selection. It also addresses ethical issues that would arise in more 
speculative scenarios of selecting embryos for hearing ability or sexual 
orientation. The article concludes that except for sex selection of the first 
child, most current extensions of PGD are ethically acceptable, and provides a 
framework for evaluating future extensions for nonmedical purposes that are 
still speculative.