THE NORMALIZATION PERIOD OF PLATELET-AGGREGATION IN NEWBORNS

This study was performed to investigate the normalization period of th e transient platelet dysfunction of newborns. A total of 43 healthy ne wborns of healthy mothers who had received no medication for at least 14 days prior to delivery were included in the study. Venous blood sam ples of 44 healthy volunteer adults were used as control. Platelet agg regation study was performed in whole blood by impedance aggregometry. Collagen or ADP was used as the aggregating agent. In the platelet ag gregation studies using collagen, maximum aggregation values in the fi rst three days of life were lower than those of adults (p<0.001). Thes e lower values were improved acid reached adult values between the 5(t h) and 9(th) day of life. Lower maximum aggregation values were observ ed in newborns in comparison with those of adults when ADP was used, b ut the difference was not significant except for 5 mu M concentration of ADP. There was no significant difference between the aggregation ti me of the collagen and ADP groups (p>0.05), In conclusion, the platele t responses to ADP and collagen were increased in newborns as the age progressed and reached normal levels between 5(th) and 9(th) day of li fe. If platelet dysfunction does exist after the 10(th) day of life, t his finding may be due to either simple prolongation of the physiologi cal phenomenon or platelet disorders.