Plasma and Red Blood Cell Folate During Normal Pregnancies

Abstract

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.

Serum and red blood cell folate levels in parturients, in the intervillous space of the placenta and in full-term newborns

“…The fact that the levels of red blood cell folates in the intervillous space of the placenta were, on the average, almost identical to those in the mother and the fact that the correlation coefficient between them was close to one indicate that the erythrocytes suffer no alterations in terms of their folate stores when circulating in the intervillous space of the placenta. Positive correlation has been reported between serum and red blood cell folate concentrations [2,3,5,7] and the results obtained in the present paper confirm these observations. Thus, the correlation existing between the red blood cell folate levels in mothers and newborns may simply be the consequence of the correlation between serum folate levels in the mother-newborn binomium.…”

“…Several studies have shown that serum and red blood cell folate levels in full-term newborns are higher than in their mothers [2,5,10,14], and these observations were confirmed in the present investigation. This fact suggests the presence of a mechanism that guarantees adequate amounts of this vitamin to the fetus.…”

“…They are especially important during pregnancy when the demand for folates greatly increases, with a consequent tendency to drops in folate levels as pregnancy progresses [6, 13,15]. It has been well established that serum and red blood cell folate concentrations are higher in full-term newborns than in their mothers [2,5,10,14]. Some investigators have suggested that the placenta may concentrate folates, thus guaranteeing high concentrations of this vitamin to the fetus [4,12].…”

Pharmacokinetics and bioavailability of folic acid and plasma levels of bioactive folates after folic acid administration to pigs

“…Efficacy of FA administration A relation between maternal folate status and reproductive performance is reported to exist in several species including humans (4,15,19), rats (21), guinea pigs (7), and pigs (6, 9,10,12,20,22,23). It has been considered that folate requirement increases during pregnancy (8).…”

First-trimester serum folate levels and subsequent risk of abortion and preterm birth among Japanese women with singleton pregnancies

“…This hypothesis suggests a possible relation between the folate status in the mother and fetal growth. Indeed, the effects of folate on increases in birthweight have been observed with some consistency among poorly nourished women [7,8].…”