Upadhyay, AmitAggarwal, RajivDeorari, Ashok KPaul, Vinod K2002-01-062009-05-302002-01-062009-05-302002-01-06Upadhyay A, Aggarwal R, Deorari AK, Paul VK. Polycythemia in the newborn. Indian Journal of Pediatrics. 2002 Jan; 69(1): 79-82http://imsear.searo.who.int/handle/123456789/8019918 references.Polycythemia is defined as a venous hematocrit above 65%. The relationship between viscosity and hematocrit is almost linear till 65% and exponential thereafter. Increased viscosity of blood is associated with symptoms of hypo-perfusion. The hematocrit in a newborn peaks at 2 hours of age and decreases gradually after that. The etiology of polycythemia is related either to intra-uterine hypoxia or secondary to fetal transfusion. Clinical features related to hyperviscosity may affect all organ systems and this entity should be screened for in high-risk infants. Polycythemia maybe symptomatic or asymptomatic and guidelines for management of both types are provided in the protocol.engBlood ViscosityHematocritHumansIncidenceInfant, NewbornPolycythemia --diagnosisJournal Article