Assessing liver function and hyperbilirubinemia in the newborn. National Academy of Clinical Biochemistry.

In clinical practice, "liver function" is assessed by either measuring the concentration of substances produced by the hepatocyte, measuring the serum content of substances that are changed by hepatocyte damage, evaluating the serum concentrations of substances released from the cells as a result of injury, assessing the ability of the liver to perform a metabolic task such as conjugation or detoxification, or by measuring enzyme activity and substrate content of the cell and its organelles. After birth, with cessation of placental function, the neonatal liver must assume many different tasks. Distinct developmental sequences rapidly progress for numerous hepatic functions as the newborn adapts to its environment. This manuscript is an attempt to provide guidelines for the evaluation and management of the newborn infant when assessing liver function and hyperbilirubinemia. These guidelines, like all sets of guidelines, are only recommendations and do not substitute for good clinical judgment based upon the individual circumstances of each patient.