Lipid peroxidation products, selenium-dependent glutathione peroxidase and vitamin E in normal pregnancy.

Twenty healthy women with normal pregnancy were simultaneously analysed with regard to lipid peroxidation products, selenium-dependent glutathione peroxidase and vitamin E. Conjugated diene double bonds, fluorescent chromolipids and thiobarbituric acid-reactive material were analysed as breakdown products of lipid peroxidation. The level of conjugated dienes in serum rose more than 45% when pregnancy advanced from the first to second trimester, but after that it declined almost to the same level as in the first trimester. The fluorescent chromolipids tended to behave in the same way. While the lipid peroxidation products reached their highest level in the second trimester, the activity of glutathione peroxidase rose progressively till the third trimester both in erythrocytes and platelets, in spite of the stable concentration of selenium in blood and plasma. The concentration of vitamin E in serum rose progressively till the end of pregnancy, but in the relation of vitamin E to cholesterol only a slight rising tendency was noted. We suggest that in normal pregnancy lipid peroxidation is controlled by adequate antioxidative response.