Folate status and requirement in pregnancy.

Abstract

SummarySome controversial aspects of rheumatic heart disease are discussed in the light of personal experience in Edinburgh. Symptoms are not always a reliable guide to severity, and the correct time for surgical treatment should be based on an objective assessment. Dangers of delay include progressive damage to the pulmonary circulation, lungs, right ventricle, and liver, and the risks of systemic embolism, pulmonary oedema, and pulmonary infarction.The New York Heart Association classification of disability is unreliable and a potentially dangerous guide.The concepts of the pliant valve, critical stenosis, areas of auscultation, and the ejection murmur are criticized.No relation has been found between the size of the left auricle or atrium and the incidence of embolism. There is reason to doubt the value of anticoagulants.In relation to mitral valvotomy factors influencing operative mortality, complications, traumatic mitral incompetence, systemic embolism, and restenosis are discussed, and also the influence of calcification and of associated aortic valvular disease.Reference is also made to the place of open heart surgery. Two hundred and six women attending the antenatal clinic at St. Mary's Hospital took part in the study. All were less than 16 weeks pregnant at the first attendance, and in order to eliminate iron deficiency all received 1 g. of intravenous iron dextran as four 250-mg. doses at weekly intervals. At the 20th week they were allotted to one of two groups, receiving tablets dispensed in a bottle with a grey or a red label. These were to be taken once daily, and contained either ferrous fumarate 260 mg. or ferrous fumarate 260 mg. and 100 jug. of folic acid, the survey being conducted as a blind trial.On the first attendance (average 15 weeks) blood was taken for a blood count, serum iron estimation, and folate determination of both serum and red cells. This was repeated at the 30th and 38th weeks of pregnancy and a sternal marrow aspiration was performed in the 37th-38th week. All the marrows were assessed at the end of the survey without any knowledge of the colour of tablet taken or of any of the assay results obtained.Haematological methods were those set out by Dacie and Lewis (1963). Neutrophil polymorphs having five or more distinct nuclear segments were termed hypersegmented, the normal frequency of such cells being 0 to 3 %. Marrows were regarded as showing megaloblastic haemopoiesis when megaloblastic change was present in erythroblasts. Giant metamyelocytes were usually present as well. Iron status was assessed by both serum iron estimation and staining of marrow spreads for iron by Perls's Prussian-blue method.Red cell and serum folates were determined by microbiological assay with the method of Toepfer et al. (1951) and Lactobacillus casei as the test organism. One gramme of ascorbate was added to each 500 ml. of medium. For red cell folate assay the blood was diluted tenfold in a 0.1 M phosphate-ascorbate buffer pH 6 (Hansen, 1964). In our hands this method gave red cell folate r...

Urinary Excretion Levels of Water-Soluble Vitamins in Pregnant and Lactating Women in Japan

“…The recommendation was again increased to 400 mg/d (200 mg from food folate and 100 mg from folic acid) in 1998 (53), after the bioavailability of food folate and folic acid (pteroylmonoglutamic acid, which has two-fold the bioavailability of food folate) was considered. The study on "folate status and requirement in pregnancy" was published in 1968 (54). In the report, based on serum folate levels in non-pregnant women, the authors calculated a dose of an additional 100 mg of folic acid (equivalent to 200 mg food folate) needed during pregnancy.…”

Influence of folic acid on birthweight and growth of the erythroblastotic infant. I. Birthweight.

“…This result agrees with our figure of 4 times the expected frequency of small-for-dates babies born to mothers with a serum folate level <5 jug/l. On the other hand, Chanarin et al (1968) and Varadi et al (1966) reported that megaloblastic anaemia of pregnancy had no adverse effect on the infant's birthweight. These results could perhaps be explained, if the diagnosis of megaloblastic anaemia (and folate deficiency) had been made before the last month of pregnancy and therefore presumably the mothers had been treated for some time before they actually delivered.…”

Effect of Folic Acid Supplementation on Pregnancy in the Squirrel Monkey (Saimiri sciureus)

“…In general, RBC folate values fall during pregnancy; if folate supplements are given, RBC folate values remain constant or may even rise during pregnancy (7,9). The effect of folate supplementation during pregnancy on infant birth weight has been studied in a number of human population groups.…”