[Changes in flow properties of the blood in pregnancy].

Over the past decade it has been shown that abnormalities of blood rheology exist in certain obstetrical conditions and are associated with circulatory disturbances. Hemorheological parameters (erythrocyte aggregation, rigidity of red cells, plasma viscosity, hematocrit) and biochemical factors (fibrinogen, albumin, total protein, water and sodium content of erythrocytes) were studied during pregnancy. Erythrocyte aggregation, plasma viscosity and fibrinogen rose with gestational age. Hematokrit, serumosmolality and colloidosmotic pressure decreased progressively during advancing pregnancy. In gestosis erythrocyte aggregation was significantly elevated after correction for packed cell volume. Hemoconcentration and an impaired red cell deformability were contributed significantly to the decrease in blood fluidity. These findings are of considerable relevance for the treatment of gestosis. Plasmavolume expander, such as salt poor human albumin, low molecular dextran or hydroxyethylstarch 200 will reduce hematocrit and erythrocyte aggregation and improve fetal outcome.