Newborn metabolic screening and related pitfalls.

Newborn screening has recently been transformed by our enhanced knowledge of medical disorders and our ability to detect and manage them. The Missouri State Newborn Screening Laboratory incorporated tandem mass spectrometry into the newborn screening protocol in 2005. This review will highlight the new capabilities of the newborn screening laboratory and the pitfalls of screening related to preterm birth, blood transfusion and intravenous fluid administration that complicate the interpretation of screening results.