Neonatal polycythemia and chest roentgenograms.

Chest roentgenograms of 34 newborns with a hematocrit of 75 or more at the age of 12 hours were studied. An analysis was made of the findings during the first four days of life and the results were compared with those of 18 newborns with a hematocrit of 65 or less. The cardiothoracic ratio (CTR) was found to be greater in the polycythemic infants than in the non-polycythemic infants, and greatest of all in infants with symptomatic polycythemia. Prominent pulmonary vascularity and pulmonary hyperaeration were seen more often in polycythemic newborns than in non-polycythemic infants. Eleven infants in the polycythemic group and three in the non-polycythemic group had some symptoms or signs.