c) Ensure that the newborn has been receiving feedings for 24 hours prior to obtaining the specimen.The nurse should ensure that the newborn has been receiving regular feedings for at least 24 hr prior to testing.The universal newborn screening is mandated by law for all newborns. Therefore, the nurse does not need to obtain informed consent prior to obtaining the specimen.The nurse should collect a capillary blood sample via heel stick for the newborn screening. Urine is not collected for this test.Premature newborns have a delayed development of liver enzymes which can cause a false POSITIVE result.