Some observations on the changes preceding the development of megaloblastic anaemia in pregnancy with particular reference to the neutrophil leucocytes

Folate and human reproduction

The influence of folate nutritional status on various pregnancy outcomes has long been recognized. Studies conducted in the 1950s and 1960s led to the recognition of prenatal folic acid supplementation as a means to prevent pregnancy-induced megaloblastic anemia. In the 1990s, the utility of periconceptional folic acid supplementation and folic acid food fortification emerged when they were proven to prevent the occurrence of neural tube defects. These distinctively different uses of folic acid may well be ranked among the most significant public health measures for the prevention of pregnancy-related disorders. Folate is now viewed not only as a nutrient needed to prevent megaloblastic anemia in pregnancy but also as a vitamin essential for reproductive health. This review focuses on the relation between various outcomes of human reproduction (ie, pregnancy, lactation, and male reproduction) and folate nutrition and metabolism, homocysteine metabolism, and polymorphisms of genes that encode folate-related enzymes or proteins, and we identify issues for future research.

Folate status in pregnant Chinese women in Hong Kong

Hematologic and folate studies were carried out in 116 pregnant Chinese women in Hong Kong. Mean serum folate values fell progressively with pregnancy reaching subnormal levels during the puerperium. Mean red-cell folate values remained normal or high throughout, but showed a significant fall after delivery in women who carried out breast-feeding. Individually, 18 women showed hematologic abnormalities compatible with folate deficiency, but only four had subnormal red-cell folate values satisfying the strict criterion of folate deficiency, giving an overall frequency of 3.4%. Compared to primigravidae and other multiparae, gravida 2 women appeared to be at highest risk of folate deficiency.

Significance of subnormal red-cell folate in thalassaemia

Subnormal red-cell folate values were encountered in 20 of 63 thalassaemic subjects in a population with a low incidence of megaloblastosis. The abnormality was not associated with haematological changes of megaloblastosis and could not be explained on the basis of incomplete liberation of intra-erythrocytic folates, serum conjugase deficiency of vitamin B12 deficiency. Evidence is presented to indicate that it is unlikely to represent a state of subclinical folate deficiency. The exact cause of the abnormality is unknown.