Neonatal polycythemia: frequency of clinical manifestations and other associated findings.

We report the results of a two-part study examining the frequency of symptoms and other findings associated with neonatal polycythemia. In the first part of the investigation, we evaluated the occurrence and features of the disorder in a cohort of 3,768 infants born at our institution that had been screened for the disorder during a 4-year period. Fifty-five infants (1.46%) had neonatal polycythemia. Of these infants, 85% had features associated with the disorder. Frequent signs and symptoms included "feeding problems" (21.8%), plethora (20.0%), lethargy (14.5%), cyanosis (14.5%), respiratory distress (9.1%), jitteriness (7.3%), and hypotonia (7.3%). Other findings included hypoglycemia (40.0%) and hyperbilirubinemia (21.8%). Of the polycythemic infants, 14.5% had no clinical symptoms or associated laboratory abnormalities. In the second portion of the study, we reviewed the features of polycythemia in all infants so diagnosed who were born in United States Army hospitals, worldwide, during a 5-year period. There were 220,050 infants born during this period; 932 (0.42%) were diagnosed as having neonatal polycythemia. Frequent findings were hyperbilirubinemia (33.5%), hypoglycemia (13.0%), and respiratory distress (6.6%). In this large group, only 13 (1.4%) had necrotizing enterocolitis, and nine (1.0%) were thrombocytopenic. Several findings among the 932 infants were unexpected. Six of the infants (only one premature) had intracranial hemorrhages. Additionally, three of the 932 had gonadal dysgenesis and three had cystic fibrosis. We found that premature infants were not less prone to having polycythemia and that the overall frequency of the disorder was less than that which has been previously reported.