Phenylketonuria (PKU) is a hereditary metabolic disorder passed from parents to their children. To prevent this disease from being passed on to a child, it is crucial for prospective parents to be aware. The primary way to determine if a child will carry this disease is for couples planning to marry or have children to learn their genetic carrier status. Whether prospective parents are carriers can be determined through genetic tests performed with a simple blood sample. If both prospective parents are carriers, Preimplantation Genetic Diagnosis (PGD) can be applied via in vitro fertilization (IVF) to perform genetic selection. This method significantly reduces the risk of genetically transmitting Phenylketonuria to the unborn child.