Changes in the maternal essential fatty acid profile during early pregnancy and the relation of the profile to diet

Background: Although the pattern of the essential fatty acids (EFAs) change s considerably from week 10 of pregnancy to term, no information is availab le on changes in EFA concentrations in the early stages of pregnancy. Objective: The main objectives were to assess the EFA status, particularly that of 22:6n-3, in women during the first 10 wk of pregnancy and to invest igate the relation of EFA status to dietary EFA intake during this period. Design: Healthy women (n = 24) planning to become pregnant were recruited. The fatty acid composition of plasma and erythrocyte phospholipids was dete rmined before and at weeks 4, 6, 8, and 10 of pregnancy. Food intake was as sessed at entry into the study and at week 10 of pregnancy by using food-fr equency questionnaires. Results: A small but nonsignificant increase in dietary intake of 22:6n-3 w as found. The plasma phospholipid content of 22:6n-3 (% by wt) increased co ntinuously during the first 10 wk of pregnancy. At week 10 of pregnancy, th e plasma percentages of 16:0, 20:3n-6, and 20:4n-6 had increased significan tly, whereas the percentages of the 18-24-carbon saturated fatty acids, 18: 2n-6, and the ratio of n-6 to n-3 fatty acids had dropped significantly. Th e composition of erythrocyte phospholipids showed changes similar to those observed in plasma. Conclusions: Maternal plasma and erythrocyte phospholipid 22:6n-3 concentra tions start to increase in very early pregnancy, which cannot be explained by changes in dietary intake alone. This rise probably represents early mat ernal adaptations to meet the requirements of highly proliferating and diff erentiating tissues at this stage of fetal development.