1. Spina Bifida Occulta which is an opening in one or more of the vertebrae (bones) of the spinal column without apparent damage to the spinal cord.
2. Meningocele that is meninges, or in laymen 's terms, a protective covering around the spinal cord, has pushed out through the opening in the vertebrae in a sac called the "meningocele. With this type, the spinal cord remains intact. This form can be repaired with little or no damage to the nerves.
3. Myelomeningocele being the most severe form of spina bifida, in which a portion of the spinal cord itself protrudes through the back. In some cases, sacs are covered with skin; in others, tissue and nerves are exposed. Spina bifida happens in the embryo where there is a tiny ribbon of tissue that folds inward to form a tube. This structure, called the neural tube (NTD), forms by the 28th day after conception. When this process goes awry and the neural tube does not close completely, defects in the spinal cord and in the vertebrae can result. Spina bifida usually is an isolated birth defect. Although scientists believe that genetic and environmental factors may act together to cause this and other NTDs, 95 percent of babies with spina bifida and other NTDs are born to parents with no family history of these disorders. While spina bifida appears to run in certain families, it does not follow any particular pattern of inheritance. If one child has spina bifida, the risk of recurrence in any subsequent pregnancy is greatly increased, to about one in 40. If there are two
References: 1. Spina Bifida Association, "How often does Spina Bifida occur?," Retrieved December 11, 2005, http://www.sbaa.org/site/PageServer?pagename=nrc_. 2. KidsHealth, "Why do kids have Spina Bifida?," Retrieved December 11, 2005, http://www.kidshealth.org/kid/health_problems/bone/spina_bifida_p2.html. 3. Mayo Clinic, "Spina Bifida Treatment," Retrieved December 11, 2005, http://www.mayoclinic.com/health/spina-bifida/DS00417/DSECTION=8& 4. Spina Bifida Association, "Living with Spina Bifida," Retrieved December 11, 2005, http://www.sbaa.org/site/PageServer?pagename=about_living.