Hemoconcentration and pre-eclampsia.

We measured erythrocyte aggregation and hematocrit in 155 uncomplicated pregnancies and in 55 pregnant women with pre-eclampsia. In the later group we found increased erythrocyte aggregation and a higher hematocrit than in normal patients of comparable gestational age. Erythrocyte aggregation correlated well with plasma fibrinogen levels (r = 0.74) but other high molecular weight proteins such as alpha-2-macroglobulin, IgM and lipoproteins were not measured. Hematocrit showed correlation with mean arterial blood pressure (r = 0.69) and peripheral vascular resistance (r = 0.73). The possible effects of changes in hematocrit and erythrocyte aggregation on blood flow through the intervillous circulation are discussed as are the clinical implications of our findings.