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.

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spina bi·fi·da -'bif-ə-dəalso -'bīf- n a neural tube defect marked by congenital cleft of the spinal column usu. with hernial protrusion of the meninges and sometimes the spinal cord see meningocele, myelocele, myelomeningocele

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(rachischisis)

a developmental defect in which the newborn baby has part of the spinal cord and its coverings exposed through a gap in the backbone. The symptoms may include paralysis of the legs, incontinence, and mental retardation from the commonly associated brain defect, hydrocephalus. Spina bifida is associated with an abnormally high level of alpha-fetoprotein in the amniotic fluid surrounding the embryo. The condition can be diagnosed at about the 16th week of pregnancy by a maternal blood test and confirmed by amniocentesis and ultrasound, so making termination of the pregnancy possible. The risk of spina bifida is reduced if supplements of folic acid are taken by women while trying to conceive and during the first three months of pregnancy. See also neural tube defects.

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a neural tube defect characterized by defective closure of the vertebral arch, through which the spinal cord and meninges may protrude (s. bifida cystica) or may not (s. bifida occulta). Cf. rachischisis. Called also hydrocele spinalis and cleft spine.