[Polycythemia in newborn infants. II. Umbilical cord and capillary hematocrits]

Actual values for capillary hematocrits at 24 and 48 hours of life, through a hospital sample, representative of our population, were obtained; results were 58 +/- 7% (X +/- 1 DS) for both. These results were correlated to the initial hematocrit (50 +/- 5%), with had been reported in the first part of the series. The relationship between capillary hematocrits and the initial one, was very good, and between the capillary ones, was oven better. This relationship persisted after distributing the sample in four groups: Apgar, crying (if it presented before or after clamping) and the features of amniotic fluid. This demonstrates that capillary hematocrits, are as reliable as venous, central and peripheral hematocrit (in this case, from umbilical chord blood), contrary to what has been previously reported in literature. The presence of chord loop or circular, was analyzed also, when it was possible.