The Authors determined alpha 2 macroglobulin in 50 healthy pregnant women and in 50 pregnant women with EPH gestosis, using the technique of nephelometry on the Immunochemistry Analyzer. The assays were done in blood serum of the mother and umbilical cord, urine and in the amniotic fluid of the affected patients. Serum values were expressed in gr/L, and amniotic fluid and urine values in mg/L. Significant reduction was found in the pregnant women with EPH gestosis in serum values of the mothers (healthy pregnant women 2.871 g/L ± 1.015, with EPH gestosis 2.239 g/L ± 1.323, p less than 0.05), and in the umbilical cord serum (healthy pregnant women 3.351 g/L ± 0.859, affected ones 2.032 g/L ± 0.693 g/L, p less than 0.01). The reduction was also noted in the urine values but was significant one. The importance of these determinations is presented in the discussion.