A neural tube defect (NTD) is a type of defect in which the structure that forms the brain and spinal cord (i.e., neural tube) fails to develop properly during the first four weeks of pregnancy. A defect in the neural tube usually results in some degree of physical and neurological impairment. The three main types of NTDs, aneincephaly, spina bifida, and encephalocele, comprise over 90% of all NTD cases. Numerous studies have shown that the daily intake of folic acid decreases a woman's risk for having a pregnancy affected with an NTD by up to 85%. Women should take a daily multivitamin containing 400 micrograms of folic acid in addition to eating a healthy diet. In order for this vitamin to be effective, it is important that women of childbearing age consume this amount of folic acid at least two months prior to conception and throughout the first trimester of pregnancy.
Anencephaly occurs when the cranial portion of the neural tube fails to close, resulting in incomplete development of the brain. Infants with anencephaly are unable to survive outside of the womb. They are either stillborn or die shortly after birth.
Encephalocele is the failure of part of the cranium to close and part or all of the brain develops outside of the skull. Many of these infants survive, but usually have developmental problems.
Spina bifida is the most common NTD. It occurs when the neural tube fails to close along a portion of the spine, leaving the spinal cord and its membranes exposed. The opening must be surgically repaired. Individuals with spina bifida often have associated conditions such as hydrocephaly (water on the brain), clubfoot, mental retardation, muscle weakness/paralysis, loss of bladder and bowel control, as well as other complications.
Between 1998 and 2007, approximately one in every 2,000 Florida live births was affected by a NTD. Of the over 900 infants born with a NTD, 699 were born with spina bifida. The average life-time medical costs for an infant with spina bifida now exceeds $600,000. Using this figure, this group of infants will have over $4 billion in medical cost over their lifetime.
Information about central nervous system (CNS) and neural tube defects (NTDs) can be found at the following sites:
Information about folic acid can be found at the following sites:
*Birth defects image credit: Centers for Disease Control and Prevention, National Center on Birth Defects and Developmental Disabilities