This information fact sheet on screening newborns to prevent mental retardation defines newborn screening and outlines how screening is performed. It discusses the six most common disorders resulting in mental retardation for which states most commonly screen. These include phenylketonuria, congenital hypothyroidism, galactosemia, maple syrup urine disease, homocystinuria, and biotinidase deficiency. A chart lists, for each of the 50 states and the District of Columbia, the status of screening for each of these disorders. (Contains 10 references.) (JDD)