URMC / Encyclopedia / Collection Blood Disorders Blood Types in Pregnancy Hemolytic Disease of the Newborn (HDN) Vitamin K Deficiency Bleeding (VKDB) in Newborns Hydrops Fetalis Hyperbilirubinemia in the Newborn Hypocalcemia in the Newborn Hypoglycemia in a Newborn Baby Overview of Blood and Blood Components Polycythemia Vera in Children Thrombocytopenia in the Newborn