The fetal cells and AFP in this fluid are studied to diagnose birth defects such as neural tube defects and chromosome problems such as Down syndrome. In the first weeks of pregnancy when the fetus is less than one inch long, the brain and spinal cord begin to form a structure along the fetal back known as the neural tube. Neural tube defects occur when the neural tube does not close properly around the brain or spinal cord. The two major types of neural tube defects are spina bifida and anencephaly. About one in 1,000 pregnancies in Iowa results in the birth of an infant with a neural tube defect.
Half have spina bifida and half have anencephaly.
The severity of the problem depends upon where the defect in the spinal cord is located. The problems may range from weakness of the leg muscles to actual paralysis. A higher defect on the spine will result in more paralysis in the legs. 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. Corrective surgery and physical therapy can help lessen the disability in these children.