Factors influencing blood viscosity: adult and newborn blood analysis.

ABSTRACT

Our finding of a decrease in blood viscosity in newborn infants compared with adults leads to analysis of this change by measuring blood viscosity, plasma fibrinogen concentration, plasma viscosity and mean corpuscular volume (MCV) of 24 adults and 16 newborn infants. Plasma proteins in newborn infants are synthesized to a lesser extent than in adults, therefore plasma fibrinogen concentration of newborn infants is less than that of adults. This causes decreased blood viscosity in newborn infants compared with adults. Secondly plasma viscosity of newborn infants is also less than that of adults. In the same situation this causes a decrease in blood viscosity in newborn. Thirdly. MCV of newborn infants is greater than that of adults because of young red cells. There is a negative correlation between blood viscosity and MCV. High MCV in newborns leads to low blood viscosity in newborn infants, compared with adults.