Polycythemia in the newborn.
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.
Upadhyay
Amit
A
Division of Neonatology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
Aggarwal
Rajiv
R
Deorari
Ashok K
AK
Paul
Vinod K
VK
D001809:Blood Viscosity; D006400:Hematocrit; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D011086:Polycythemia / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology / Q000628:therapy*