By the immunochemical method the authors determined alpha 1 acid glycoprotein in 20 pregnant women with normal pregnancy and 60 pregnant women with diabetes mellitus, EPH gestosis, and imminent abortion. In women with normal pregnancy no statistically significant changes between individual trimesters were recorded. Pregnant women with diabetes mellitus showed a statistically significant increase in all three trimesters, those with EPH gestosis in the first and the second trimester, and those with imminent abortion only in the first trimester. In the authors' opinion, the test could be a useful parameter in following up pathologic pregnancies.