Spina bifida is a neural tube defect that usually runs in families. Spina bifida occurs due to an abnormality in the development of the spinal cord in the first trimester of pregnancy. The defect can only be associated with a protrusion of the membrane that covers the spinal cord (meninges), called a meningocele, or with some neural elements, called a meningomyelocele. Spina bifida can cause mild to severe physical and mental disabilities, depending on the size and location of the opening in the spine, and whether the spinal cord and nerves are affected. Myelomeningocele is a defect in which a fluid sac containing part of the spinal cord and nerves exits through an opening in the baby's spine, causing nerve damage. Also called "open spina bifida," this disease causes moderate to severe disabilities, such as trouble going to the bathroom, loss of sensation in the legs or feet and paralysis in the legs.
