Evaluation of erythrocyte hyperaggregation in fetal blood drawn by cordocentesis as a marker of fetal diseases

(Accepted by Guest Editor O. Linderkamp) Fetal blood can now be routinely studied by intrauterine sampling. Low erythrocyte aggregability is one of its most prominent hemorheological characteristics before 32 wk gestation. We investigated whether increased RBC aggregability is a marker of fetal pathologies. After we established in 119 fetuses a control group for fetal blood rheology, we measured erythrocyte aggregation with the Myrenne apparatus (i.e. a micromethod using 1 droplet of blood) in 111 fetuses explored for various diseases. RBC aggregation was increased (>2 Sd for gestational age) in 24 fetal blood samples, with the following diseases: 12.5% toxoplasmosis; 12.5% rhesus immunization; 8.33% autoimmune thrombocytopenia; 8.33% kidney polycystosis; 8.33% old maternal age; 8.33% heart malformation; 8.33% fetal hypotrophia. In autoimmune diseases (rhesus; thrombocytopenia) RBe aggregation was increased in 5/10 cases (50%); in heart or kidney malformations 5/10 (50%); in toxoplasmosis seroconversion 3/23 i.e. 13% of the fetuses had increased aggregation. These data suggest that RBC aggregation is increased in several fetal diseases and may be a nonspecific marker of them. key words: fetal blood, cordocentesis, hemorheology, erythrocyte deformability, blood viscosity. erythrocyte aggregation. 638 RBC AGGREGATION IN FETAL BLOOD Vol. 14, No.5