Background: Although the pattern of the essential fatty acids (EFAs) changes considerably from week 10 of pregnancy to term, no information is available 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 investigate 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 determined before and at weeks 4, 6, 8, and 10 of pregnancy. Food intake was assessed at entry into the study and at week 10 of pregnancy by using food-frequency questionnaires.
Results: A small but nonsignificant increase in dietary intake of 22:6n-3 was found. The plasma phospholipid content of 22:6n-3 (% by wt) increased continuously during the first 10 wk of pregnancy. At week 10 of pregnancy, the plasma percentages of 16:0, 20:3n-6, and 20:4n-6 had increased significantly, 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. The composition of erythrocyte phospholipids showed changes similar to those observed in plasma.
Conclusions: Maternal plasma and erythrocyte phospholipid 22:6n-3 concentrations start to increase in very early pregnancy, which cannot be explained by changes in dietary intake alone. This rise probably represents early maternal adaptations to meet the requirements of highly proliferating and differentiating tissues at this stage of fetal development.