Here are four arguments against sex selection: 1. It encourages ‘parenting by stereotype’, where the desire to have a child of a certain gender may be based on a stereotypical ideal of what that gender is supposed to be like. 2. It is typically done in favour of males, leading to a significant shortage of females, which causes a myriad of serious problems. 3. It gives Preimplantation Genetic Diagnosis (PGD) a bad name. PGD is utilised to screen out a panoply of genetic disorders such as Lou Gehrig's Disease, breast cancer, and cystic fibrosis. Using it to screen out an unwanted gender is a poor way to deploy scarce medical resources and know-how. 4. It could be a gateway to eugenics, the widely condemned theory of improving humanity by preventing inferior people from reproducing while encouraging reproduction of those judged to be superior.