Folic acid and pregnancy, benefit or risk?

Abstract

Acid folic intake has been related to the decrease in the incidence of congenital malformations and obstetric deficiencies but there are criteria about folic acid not always achieving the expected favorable results for mothers and their descendants. A search on the theme was carried out with the objective of structuring the theoretical assumptions upholding the benefit and risk of folic acid intake for pregnancy. 37 updated bibliographic references were consulted. 

The folic acid has two main functions in the organism: nucleic acids´ synthesis and repair, and also the synthesis of the methionine amino acid from homocystein; when the last one accumulates in the organism, it is associated to congenital defects and adults´ chronic diseases. Beginning from these aspects, it is stated that the intake before and after pregnancy is beneficial because it prevents defects of the neural tube, some congenital deficiencies,  oral facial clefts, Down syndrome, autism spectrum disorders, obstetric infections, preeclampsia, uterine hemorrhage, sudden placental abruption, intrauterine grow retardation and prematurity. The excessive intake of more than 5 mg/d has been associate to anemia due vitamin B12 deficiency, zinc deficiency, intrauterine retarded grow and prematurity; in animal models it speeds up the malignant transformation of existent tumors. The authors arrived to the conclusion that folic acid contributes to preserving a normal embryogenesis and placentation, and that no adverse effects have been demonstrated, nevertheless it should be taken in adequate doses and for medical prescription.