MATERNAL AND NEONATAL PLASMA ANTIOXIDANT LEVELS IN NORMAL-PREGNANCY, AND THE RELATIONSHIP WITH FATTY-ACID UNSATURATION

During pregnancy, maternal plasma concentrations of the peroxidation-s usceptible polyunsaturated fatty acids (polyenes) increase. In additio n, the proportion of polyenes is higher in neonatal plasma than in mat ernal plasma. To study whether these increased amounts of polyenes aff ect antioxidant levels, we measured lipid-soluble antioxidants in mate rnal and neonatal plasmas obtained during thirty-five normal pregnanci es. These values were then related to the degree of phospholipid-fatty acid unsaturation. Maternal plasma levels of tocopherols and lutein i ncreased during pregnancy, as assessed at 14, 22, and 32 weeks of gest ation. However, beta-carotene levels decreased, and levels of other ca rotenoids remained unchanged. Retinol levels were only decreased at 32 weeks of gestation. The value for alpha-tocopherol: phospholipid-poly ene unsaturation index (UI) also increased during pregnancy, despite t he observed increase in UI. Corresponding ratios for several carotenoi ds and retinol, however, decreased during pregnancy. After delivery, m aternal plasma levels of delta-tocopherol and beta + gamma-tocopherol, as well as beta + gamma-tocopherol:UI values, were lower than values at 32 weeks of gestation. Umbilical-cord plasma antioxidant levels and antioxidant:UI values, except retinol:UI, were significantly lower th an maternal values. Significant and consistent cord nu. maternal corre lations were observed for plasma levels of beta + gamma-tocopherol, lu tein and beta-carotene, but not for delta-tocopherol, alpha-tocopherol , lycopene, alpha-carotene, and retinol. In conclusion, although durin g pregnancy maternal plasma tocopherol levels increased concurrently w ith, or more than, fatty acid unsaturation in plasma phospholipids, th e decrease in carotenoid:UI values during gestation, the decrease in m aternal plasma levels of delta-tocopherol and beta + gamma-tocopherol after delivery, and the low neonatal antioxidant levels merit further investigation.