title: Folic acid consumption throughout pregnancy: differentiation between trimesters.
abstract: Intervention trials have demonstrated conclusively that oral ingestion of extra folic acid can prevent the majority of cases of spina bifida and other neural tube defects (NTDs). Data from these studies offer conclusive evidence that the intake of 400 μg/day folic acid provides this benefit. The big problem has remained that the neural plate closes to form the neural tube between day 21 and day 28 postconception, at which point most women do not even realize that they are pregnant. This, coupled with the fact that over half of all pregnancies are unplanned, has resulted in many studies showing that less than one-fifth of pregnancies have followed the recommendation for prevention. However, where compliance has been good or where folic acid has been added mandatorily, there has been the expected reduction in NTDs. Clarity regarding what is recommended for early pregnancy does not carry through to the second or third trimester of pregnancy where practices vary widely not only from country to country but even from clinician to clinician within particular countries.
authors: School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland. jscott@tcd.ie
authors: John
authors: J
authors: Scott
mesh_terms: D000328:Adult; D000818:Animals; D000013:Congenital Abnormalities / Q000517:prevention & control*; D019587:Dietary Supplements; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D039382:Maternal Nutritional Physiological Phenomena; D009436:Neural Tube Defects / Q000517:prevention & control; D017410:Practice Guidelines as Topic; D016742:Preconception Care; D011247:Pregnancy; D011264:Pregnancy Trimesters; D011295:Prenatal Care; D055502:Secondary Prevention
chemical_list: D005492:Folic Acid