The spinal cord containing the deeper nerves of the spinal column protrudes from the open spine without a protective covering of the skin. Spinal fluid may leak out and infection can be a serious problem. This defect usually occurs at the lower end of the spine resulting in paralysis of the baby's legs along with poor bladder and bowel control. In North America, NTD's occur in one or two out of every 1,000 births. A family history of NTD's also increases the possibility of having a child with one of these defects.
Neural defects are in a category of birth defects called polygenic or multifactorial.
This means that NTDs are caused by one or more genes interacting with an environmental factor. Environmental triggers for NTDs that are being studied include viruses, vitamin and mineral deficiencies, chemicals, drugs, and maternal illness like diabetes. If you know ahead of time that your baby may be born with an NTD, you can arrange for prompt and expert medical treatment. The AFP screening test measures the amount of a substance called alpha-fetaprotein in the mother's blood. The most severe neural tube defects will often leak AFP resulting in an increase in AFP levels in the mother's bloodstream.