Preimplantation Genetic Diagnosis or PGD tests a woman’s embryos outside of her body for genetic sequence that are linked to a variety of conditions. PGD was developed for couples at risk for passing on a serious genetic mutation. Since 1999 it has been most widely used to prevent the birth of children with conditions such as Down syndrome, Tay-Sachs disease, cystic fibrosis, sickle cell, Huntington’s chorea, and Cooley’s anemia. However, PGD is increasingly being used for other reasons. These include social sex selection, creating “savior siblings” who can provide bone marrow and other transplant tissues to sick older siblings, and selecting against embryos with genes correlated with late-onset and non-fatal conditions. Some clinics have even offered the technique for purely cosmetic traits including eye color, hair color, and skin complexion (geneticsandsociety.org). It also contributes to concerns over the creation of what are critically called designer babies, though the…