Spina bifida: A birth defect (a congenital malformation) in which there is a bony defect in the vertebral column so that part of the spinal cord, which is normally protected within the vertebral column, is exposed. People with spina bifida can suffer from bladder and bowel incontinence, cognitive (learning) problems and limited mobility.
Spina bifida is caused by the failure of the neural tube to close during embryonic development. The neural tube is the embryonal structure that gives rise to the brain and spinal cord.
The risk of spina bifida varies according to country, ethnic group and socioeconomic status. In the US as a whole, spina bifida occurs in about one in every 1-2,000 births. The risk of spina bifida and other neural tube defects such as anencephaly can be decreased by women taking folic acid supplements before they conceive and during the first months of their pregnancy.
For more information about neural tube defects, see Spina Bifida & Anencephaly. Spina bifida is sometimes referred to as meningomyelocele.