Association of anaemia in pregnancy and folic acid deficiency

FOLIC ACID AND VITAMIN B12 LEVELS IN PREGNANCY AND THEIR RELATION TO MEGALOBLASTIC ANAEMIA

There is a significant fall in the serum folic acid level during pregnancy, reaching its lowest level at term. This is most pronounced in twin pregnancies. A similar but less spectacular fall occurs in the vitamin B(12) concentration. In megaloblastic anaemia both folic acid and vitamin B(12) levels are lower than in other pregnant women. The degree of megaloblastic change in the bone marrow, as measured by the type and number of megaloblasts, is reflected in the vitamin levels, cases with florid megaloblastosis showing the most marked depression of vitamin B(12) and folic acid activity. Although there is a significant difference in the mean folic acid levels between megaloblastic and normoblastic pregnant women, a considerable overlap exists between individual values in the two groups. When the labile folic-acid factor is determined separately the test becomes much more specific. In the present series, all cases of megaloblastic anaemia yielded labile-factor levels below 1.0 mmug. per ml., while a similar value was encountered in only one of 35 normal pregnancies. In five women with megaloblastic anaemia the vitamin B(12) concentration was less than 100 mumug. per ml. but rose to normal levels on folic acid therapy alone.

Folic acid deficiency in the United States: folate assays in a prenatal clinic

Tissue deficiency of folic acid, as measured by a red cell folate level below 150 ng. per milliliter, was present in 16 per cent of 110 sequential pregnant women at the time of their first prenatal visit to a municipal clinic. A further 14 per cent of subjects had red cell folate levels in the range "suggestive but not conclusive for tissue folate depletion" (150 to 199 ng. per milliliter). All of the subjects were from low-income families in New York City and most were black or of Puerto Rican origin. Serum folate levels showed good general correlation with red cell folate but were of less value as a diagnostic test, since they were below the lower limit of normal in 64 per cent of subjects, including many subjects who did not yet have low tissue folate. In contrast to their value in other folate deficiency states, neutrophil lobe counts showed no correlation with serum or red cell folate levels in pregnancy and thus appeared of little diagnostic value in pregnancy. It is suggested that surveys of folate deficiency in other pregnant population groups in the United States be carried out. These results support the recommendations of the Committee on Maternal Nutrition and the Committee on Dietary Allowances of the Food and Nutrition Board, National Research Council (U.S.A.) that folic acid supplements (200 to 400 mug per day) should be taken throughout pregnancy.