Vitamin supply in pregnancy for prevention of congenital birth defects.

PURPOSE OF REVIEW: After the short summary of history of primary prevention of neural tube defects by folic acid or folic acid-containing multivitamin supplementation during the periconception period, the three main unsolved problems are highlighted.

RECENT FINDINGS: Both intervention trials and observational studies confirmed that this new primary preventive method is effective - beyond the prevention of neural-tube defects - in the reduction of the most common structural birth defects: congenital cardiovascular abnormalities. Nevertheless, this important progress in the field of congenital abnormalities is not appreciated appropriately. The periconception supplementation of both folic acid alone and folic acid-containing multivitamin is useful; however, the available data indicate the higher efficacy of multivitamins in the primary prevention of neural-tube defects and congenital cardiovascular abnormalities. The optimal dose of folic acid is not known though this knowledge would be necessary from both a scientific and practical aspect.

SUMMARY: Periconception folic acid or folic acid-containing multivitamin supplementation has resulted in a breakthrough in the primary prevention of neural-tube defects, cardiovascular abnormalities and probably some other defects; however, extra efforts are necessary to eliminate folic acid or folic acid-containing multivitamin preventable congenital abnormalities.