Plasma and red blood cell folate during normal pregnancies.

Plasma and red cell folate concentrations (Lactobacillus casei activity) have been studied in 43 women during pregnancy. Iron, but no folic acid supplement was given. The plasma folate concentrations decreased significantly during pregnancy and were lower than in the reference cases at term. The red cell folate concentrations were compatible with the reference material during early pregnancy, and significantly higher than the reference material at term. A significant decrease was observed during the last two months of pregnancy. The plasma folate and the red cell folate concentrations at different stages of pregnancy were correlated and a relationship was demonstrated between these parameters at different stages of pregnancy. The hemoglobin concentrations were compatible with the reference material during early pregnancy and at term. One hundred and sixty-six women were also studied at term to evaluate the effect of repeated pregnancies on the folate status. Repeated pregnancies did not influence the plasma and red cell folate concentrations at term. We conclude that the folate intake is adequate to meet the increased requirements during pregnancy, and folic acid supplementation is therefore not recommended as a routine in normal pregnancies in this population.