In a double-blind study, 12 patients with an Hb > 13 g/dl in the second trimester, a pretherapeutic hematocrit > 38%, and a fetal aortal resistance index > 0.75 underwent hemodilution. The patients were given either 500 ml hydroxyethyl starch (HAES) or 500 ml NaCl 0.9%. In addition, all patients received 500 ml NaCl 0.9% by infusion. HAES therapy caused a lowering of the fetal aortal and uterine artery resistance indices. This was not the case with NaCl. The causes for this lie in the specific anti-aggregation and viscosity-reducing effect of hydroxyethyl starch with an identical lowering of hematocrit.
Blood Flow Velocity Double-Blind Method