Spina Bifida – What is Spina Bifida?
Spina bifida is a serious birth defect that occurs when the tissue surrounding the developing spinal cord of a fetus does not close properly during the first month of pregnancy. It is part of a group of birth defects called neural tube defects, a disorder involving incomplete development of the brain, spinal cord, and/or their protective coverings.
In babies with spina bifida, a portion of the neural tube fails to develop or close properly, causing defects in the spinal cord and in the bones of the backbone. Infants born with spina bifida sometimes have an open lesion on their spine where significant damage to the nerves and spinal cord has occurred. Although the spinal opening can be surgically repaired shortly after birth, the nerve damage is permanent, resulting in varying degrees of paralysis of the lower limbs. Even when there is no lesion present there may be improperly formed or missing vertebrae and accompanying nerve damage. In addition to physical and mobility difficulties, most individuals have some form of learning disability. Spina bifida may also cause bowel and bladder complications, and many children with spina bifida have hydrocephalus (excessive accumulation of cerebrospinal fluid in the brain).
The three most common types of spina bifida are:
- Myelomeningocele. The severest form, in which the spinal cord and its protective covering (the meninges) protrude from an opening in the spine.
- Meningocele. The spinal cord develops normally but the meninges protrude from a spinal opening.
- Occulta. The mildest form, in which one or more vertebrae are malformed and covered by a layer of skin.
Spina bifida is one of the more common birth defects in the United States. The incidence of spina bifida can be decrease by up to 70 percent when a daily folic acid supplement is taken prior to conception.