A short-term supplementation of pregnant women before delivery does not improve significantly the vitamin E status of neonates--low efficiency of the vitamin E placental transfer.

Little is known about lipid-soluble vitamin placental transfer. We supplemented ten pregnant women ranging in age from 26 to 38 years with vitamin E at a daily dose of 1 g dl-alpha-tocopherol acetate for 3 days before delivery. All pregnancies ranged from 37 to 39 weeks of gestation at the time of the study. Maternal blood was first drawn during the week preceding supplementation and then just before the delivery by hysterotomy. Neonatal blood was from cord at birth. Supplementation dramatically increased the plasma and red blood cell vitamin E of the mothers. This was true whatever the expression of the vitamin E content, i.e., plasma lipid-normalized or non-normalized vitamin E, and red blood cell vitamin E related to volume of packed cells or to membrane-phospholipid phosphorus. In contrast, the plasma vitamin E content was very low in neonates (3.51 +/- 0.38 mg/L) and did not significantly differ from that reported in a previous paper, where plasma was drawn from fetal cord blood of pregnant non-supplemented women belonging to the same geographical population (Cachia et al., Am. J. Obstet. Gynecol. 1995; 173: 42-51). This strongly suggests that the transfer of vitamin E through the placental barrier is very low. That the plasma lipid-normalized levels of mothers before supplementation and of neonates did not significantly differ also suggests that the paucity of lipids in the circulating blood of neonates is the cause of the restricted amount of plasma vitamin E. Therefore, the low level of vitamin E in neonates may result from both low maternal placental transfer and neonatal lipid transport peculiarities.