Diagnostic value of arterial hematocrits in neonatal polycythemia

In order to study the correlation among arterial, capillary and venous hematocrits, sixty newborn babies delivered in our hospital were chosen after receiving their parents' consents for hematocrits study within their first eight hours of life. The venous hematocrits of them (59.77 +/- 14.15%) correlate with arterial hematocrits (57.84 +/- 14.36%) very well (r = 0.95, p less than 0.001). Whereas, the venous and arterial hematocrits correlate with capillary hematocrits (66.63 +/- 15.56%) also significantly (r = 0.72, p less than 0.001 for both). Arterial hematocrits of more than 62% is proportionate to venous hematocrits of 64% and above. The relationship between arterial and venous hematocrits does not change even after we divide the subjects into those venous hematocrits above 64% and those below 64%. Furthermore, the capillary hematocrits of above 70% can be used as the criteria of polycythemia in the neonatal screening. If the capillary hematocrit is above 70%, then venous hematocrit should be checked for the confirmation of polycythemia.