The article considers the results of analysis of content of regulative transport proteins in blood serum and urine of pregnant women (term III) in case of uncomplicated pregnancy and pregnancy complicated by preeclampsia and eclampsia for elaborating their pathogenic role and evaluating prognostic significance. It is established that the more severe eclampsia is the higher is the level of a2-macroglobulin and the lower is the content of lactoferrin in blood. At that, excretion of a2-macroglobulin and albumin with urine increases with aggravation of severity of processes and in urine is detected a1-antitrypsin previously undetected. The excretion of lactoferrin reaches its peak values in case of preeclampsia and decreases in case of eclampsia. The alteration of levels of a2-macroglobulin and lactoferrin are uncharacteristic for classic inflammatory reaction and testify their active involvement into pathogenesis of eclampsia. The decreasing of in blood of levels of a1-antitrypsin lesser than 5 g/l and lactoferrin lesser than 0.8 mg/l at concentration of a2-macroglobulin higher than 3.5 g/l against the background of decreased levels of albumin and crude protein in blood and also increasing in urine of concentrations of a2-macroglobulin up to 0.0005 g/l and higher and occurrence of a1-antitrypsin and increasing of content of albumin up to 10 times can be recommended as criteria of high risk of development of eclampsia in regnant women with moderately expressed preeclampsia in term III.