Evaluation and Modification of Whole Blood Filtration in the Measurement of Erythrocyte Deformability in Pregnancy and the Newborn

Abstract

The deformability of erythrocytes from pregnant women and full-term newborn infants, with healthy female adults as a comparison, using a whole blood filtration method, was investigated. Delay in measurement, white cells, hematocrit, plasma viscosity, temperature and pH all significantly affected the rate of whole blood filtration and could thereby obscure or exaggerate changes in erythrocyte deformability. A new method was developed which eliminated or minimized these sources of error and the study was completed. Fetal erythrocytes were significantly less deformable than adult erythrocytes which were in turn significantly less deformable than erythrocytes from pregnant women. These differences appear to be related to the varying plasma fibrinogen concentrations in the 3 groups of subjects. The significance of these findings in the special hemodynamic situations found in the neonate and during pregnancy was discussed.