Spina bifida (Myelodysplasia)

How is spina bifida diagnosed?

Severe cases of spina bifida are obvious at birth, with the fluid-filled sac protruding from the newborn’s back. Visual indicators of the lesser form (spina bifida occulta) may include a hairy patch of skin or a dimple along the spinal column. Unusual weakness or lack of coordination in the lower limbs also suggests spina bifida.

In babies who are less than 4 months, spinal ultrasounds can be used to detect spinal cord tethering and other abnormalities of the spinal cord.

Prenatal testing

Diagnostic tests can also be performed during pregnancy to evaluate the fetus for spina bifida.

These include:

• Blood tests: The American College of Obstetricians and Gynecologists recommends a blood test between 15 and 20 weeks of pregnancy for all women who haven’t previously had a child with an open neural tube defect (ONTD) and who don’t have a family history of ONTD:

• The blood test measures alpha-fetoprotein (AFP) levels and other biochemical markers in the mother's blood to determine whether her pregnancy is at increased risk for an ONTD.

• Although the test can’t diagnose an ONTD with 100 percent accuracy, it can predict which pregnancies are at greater risk, so that additional testing can be performed as the pregnancy progresses.

• Amniocentesis: a procedure that involves inserting a long, thin needle through the mother’s abdomen into the amniotic sac to withdraw a small sample of the amniotic fluid for examination. The fluid is tested to determine the presence or absence of an open neural tube defect (ONTD) like spina bifida. Although very reliable, this test may not pick up small or closed defects.
   
• Prenatal ultrasound (sonography): a diagnostic imaging technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues and organs. The spinal defect can sometimes be detected on the ultrasound study and can also be used to examine the fetus’ other organs and body systems.