Fibronectin is a high-molecular polyfunctional glycoprotein occurring in the majority of the body fluids and tissues. Various investigations have demonstrated that plasma fibronectin levels either fail to change, or increase with longer gestation during a normal pregnancy. The time course of changes in fibronectin levels has been found to become lower in the amniotic fluid during pregnancy, though its physiological role has not been defined in this case. In late gestosis, plasma fibronectin concentrations substantially rises as compared to those observed in normal pregnancy.