Premarital screening is defined as testing couples who are planning to get married soon for common genetic blood disorders (mainly hemoglobinopathies, e.g. thalassemia and sickle cell anemia) and infectious diseases (e.g. hepatitis B, hepatitis C, and HIV/AIDS).

People with Rh compound are termed as Rh-positive and people without the Rh compound are known as Rh-negative. It is very important that couples get their Rh checked before getting married or having a child, as it can raise complications in the baby.