[Hemorheology in pregnancy and fetal growth]

The relationship between fetal birth weight and maternal hemorheological factors in 37-41 weeks of gestation were investigated in pregnant women who delivered normal and small for gestational age singleton infants without malformation. Blood viscosities were measured at low shear (0.5 sec-1) and high shear (230 sec-1) rates. Erythrocyte deformability was measured by a filtration method, which involved the measuring of a filtered volume of erythrocyte, suspended in phosphate buffer and passed through a nuclepore polycarbonate filter. The filters pores were 5 microns in diameter and the driving pressure on erythrocyte suspension was -10cmH2O. Mothers who delivered small for gestational age infants had significantly higher levels of blood viscosity at the low shear rate and lower levels of erythrocyte deformability than those who delivered normal infants. But there was no significant difference in blood viscosity at the high shear rate between the two groups. There was a significant negative correlation between the maternal blood viscosity at the low shear rate and the birth weight of their infants, and a positive correlation between the maternal erythrocyte deformability and the birth weight. From these results, it was suggested that fetal growth was affected by maternal hemorheological factors.