Management of polycythemia in neonates.

Polycythemia is defined as a venous hematocrit above 65%. The hematocrit in a newborn peaks at 2 h of age and decreases gradually after that. The relationship between hematocrit and viscosity is almost linear till 65% and exponential thereafter. Increased viscosity of blood is associated with symptoms of hypo-perfusion. Clinical features related to hyperviscosity may affect all organ systems. Neonates born small for gestational age (SGA), infants of diabetic mothers (IDM), and multiple births are at risk for polycythemia. They should therefore undergo screening at 2, 12, and 24 h of age. Polycythemia may be symptomatic or asymptomatic and guidelines for the management of both types based on the current evidence are provided in the protocol.