Preimplantation Genetic Diagnosis (PGD) is a medical procedure used during in vitro fertilization (IVF) to test embryos for specific genetic conditions before they are implanted in the uterus. This technique allows parents to select embryos that do not carry certain inherited disorders, such as cystic fibrosis or sickle cell anemia, increasing the chances of a healthy pregnancy. PGD involves taking a few cells from an embryo at the blastocyst stage and analyzing their DNA. If the tests show that the embryo is free from the targeted genetic conditions, it can be implanted, giving parents peace of mind and reducing the risk of passing on genetic diseases to their children.