Spina bifida, also called myelodysplasia, is a condition in which there is abnormal development of the back bones, spinal cord, surrounding nerves, and the fluid-filled sac that surrounds the spinal cord. This neurological condition can cause a portion of the spinal cord and the surrounding structures to develop outside, instead of inside, the body. The defect can occur anywhere along the spine and usually develops during pregnancy.
The types of spina bifida include:
A mild form of spina bifida in which the spinal cord and the surrounding structures remain inside the body, but the back bones in the lower back area fail to form normally. There may be a hairy patch, dimple, or birthmark over the area of the defect. Other times, there may be no abnormalities in the area.
A moderate form of spina bifida in which a fluid-filled sac is visible outside of the back area. The sac does not contain the spinal cord or nerves.
A severe form of spina bifida in which the spinal cord and nerves develop outside of the body and are contained in a fluid-filled sac that is visible outside of the back area. These babies typically have weakness and loss of sensation below the defect. Problems with bowel and bladder function are also common. A majority of babies with myelomeningocele will also have hydrocephalus, a condition that causes the fluid inside of the head to build up, causing pressure inside of the head to increase and the skull bones to expand to a larger than normal size.
Approximately 80 percent of defects are found in the lower back area. The remaining 20 percent of the defects are located in the back of the neck or upper back areas.
Genetic counseling may be recommended by your physician to discuss the risk of recurrence in a future pregnancy, as well as vitamin therapy (a prescription for folic acid) that can decrease the recurrence risk for ONTDs. Supplemental folic acid, a B vitamin, if taken one to two months prior to conception and throughout the first trimester of pregnancy, has been found to decrease the reoccurrence of ONTDs for couples who have had a previous child with an ONTD.