Neural Tube Defects
In the first weeks of pregnancy, when the fetus is less than one inch long, a structure known as the neural tube begins to form along the fetal back. The top of this tube develops into the brain and the rest becomes the spinal cord. Open neural tube defects occur when the skull or spine does not close properly around the brain or spinal cord.
The two major types of open neural tube defects are spina bifida and anencephaly. About one in 1,000 pregnancies in Iowa will have an open neural tube defect. About half of these have spina bifida and half have anencephaly.
Babies born with spina bifida (open spine) have an opening in the bones of the spine, which can result in damage to the nerves which control the lower part of the body. The effects from spina bifida may range from mild to severe, from weakness of the leg muscles to actual paralysis. The severity of the problem depends upon where along the spinal cord the defect is located; a higher defect in the spine will result in more paralysis. Because the nerves that direct bowel and bladder functions are at the base of the spinal cord, there may be problems with bowel and bladder control. Over 80% of newborns with spina bifida have hydrocephalus (water on the brain). Corrective surgery and physical therapy can help lessen the disability in these children so that some may lead relatively normal lives. In severe cases of spina bifida a baby may be stillborn or die soon after birth.
Anencephaly (open brain) occurs when the skull and brain do not develop normally. Babies with this severe condition are almost always stillborn or die very soon after birth.
For more information about spina bifida:
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