Influence of changes in dietary fatty acids during pregnancy on placental and fetal fatty acid profile in the rat.

To determine whether the composition of long-chain polyunsaturated fatty acids (PUFA) could be modified in the fetus by maternal dietary fatty acids, pregnant Sprague-Dawley rats were fed semipurified diets that differed only in the non-vitamin lipid component. The diets contained either 10 g palm, sunflower, olive or fish oil (FOD)/100 g diet. A total of 5-6 rats were studied in each group. At day 20 of gestation, corresponding to 1.5 days prior parturition, the fatty acids in maternal adipose tissue were closely related to the fatty acid composition in the corresponding diet. An important proportion of arachidonic acid (AA) appeared in maternal liver and plasma, although it was lower in the FOD than in the other groups. Except for saturated fatty acids, the proportion of individual fatty acids in the placenta correlated linearly with that in maternal plasma. Also, PUFA in fetal plasma and liver showed significant correlations with PUFA in maternal plasma. Again, AA showed the lowest proportion in the plasma and liver of the FOD group. Therefore, the maternal dietary fatty acid composition influences maternal and fetal plasma and tissue composition, and an increase in dietary omega-3 fatty acids decreases the amount of AA in maternal and fetal tissues. Copyright 2003 S. Karger AG, Basel