Neural tube defects

• 2nd most common birth defect contributing to infant mortality and disability
• includes spina bifida occult, myelomeningocele, meningocele, anencephaly, and encephalocele
• the cause is unknown but many factors such as drugs, malnutrition, chemicals, and genetics can adversely affect normal CNS development
• Evidence supports the need for maternal preconception supplementation of folic acid