Spina bifida is a birth defect that occurs when the spine and spinal cord do not form properly. It is a type of neural tube defect.
Normally, the neural tube forms in early pregnancy and closes 28 days after birth. In babies with spina bifida, a portion of the neural tube does not close or develop properly, causing defects in the spinal cord and spinal bones.
Spina bifida can range from mild to severe, depending on the type of defect, size, location and complications. When necessary, early treatment of spina bifida involves surgery, although such treatment does not always completely resolve the problem.