1. Markers of Spina Bifida Occulta
Spina bifida is a birth defect that affects the spinal cord. There are two forms of spina bifida--spina bifida occulta and spina bifida manifesta. Spina bifida occulta is the more common form of the defect that may affect as many as 24 percent of the population. Spina bifida occulta is very mild and does not typically have any symptoms. Most people do not even know that they have this defect. In some cases, there are small physical markers that can identify the presence of spina bifida occulta, however. These markers include a dimple, a small tuft of hair, an indentation, a fatty deposit or a birthmark over the site of the spinal defect. Most cases of spina bifida occulta are not diagnosed.
2. Characteristics of Spina Bifida Manifesta
Spina bifida manifesta comes in two different forms as well--meningocele and myelomeningocele. Meningocele is the less severe of the two and can sometimes be identified by a swollen area over the spine. It can also be shown on an X-ray. This form of spina bifida usually does not cause symptoms and can be corrected through surgery. Myelomeningocele, on the other hand, is the most severe form of this defect. With this form of the defect the spinal canal remains open causing the membrane and spinal cord to protrude out as a sac on the baby's back. In the most severe cases, the sac is not covered by skin. Surgery is required almost immediately to prevent infection and further nerve damage. In some cases of myelomeningocele, spinal fluid also builds up in the head, causing an enlarged head, or hydrocephalus.
3. Testing for Spina Bifida
Testing for spina bifida prenatally can diagnose the defect before birth. Early diagnosis in this way can help doctors prepare for the birth and put in place the necessary precautions to protect the exposed spinal cord. There are several different tests done for spina bifida prenatally, including blood tests, ultrasound and amniocentesis. The blood tests for spina bifida are not always accurate and can yield false positives, however. Following up positive blood tests with an ultrasound is standard. Some evidence suggests those with a family history of spina bifida or other similar neurological birth defects may have an increased risk of giving birth to a baby with spina bifida. Prenatal testing is usually done at the discretion of the mother. If you have a family history of neurological birth defects, a test for spina bifida is advisable.
