Birth defects: prevention of neural tube defects by periconceptional use of folic acid and screening.

Folate deficiency is one of today's most common vitamin deficiencies in women. Women who consume a low level of folate during pregnancy are at risk for poor pregnancy outcomes including birth defects. Birth defects are the leading cause of fetal and infant deaths throughout the world. Neural tube defects comprise a major portion of the birth tube defects. Neural tube defects are common and serious malformations that originate early in pregnancy. Each year in the US, about 4000 babies are born with these two most common neural tube defects, spina bifida and anencephaly. Spina bifida is the leading cause of childhood paralysis. Several studies showed that about 70% of the neural tube defects could be prevented if all women capable of becoming pregnant consumed 0.4 mg of folic acid daily before and during early pregnancy. This paper reports results from various human and animal studies.