Spina bifida is
one of a class of birth defects, called neural tube
defects. These defects involve damage to the spine
and spinal cord.
Under normal circumstances, the neural tube forms
in the developing baby in the first few weeks of
pregnancy and closes by the 28th day after
conception. Later, the top of this tube becomes the
baby's brain, and the remainder of the tube becomes
the baby's spinal cord. In babies with spina bifida,
an area along the lower end of the neural tube fails
to develop or close properly, causing defects in the
spinal cord and in the bones that make up the
backbone (vertebrae) . This can also occur in the
middle or upper end of the spine, but it's less
Spina bifida is one of the more common birth
defects. Treatment for spina bifida may involve
surgery, but it depends on the severity of the
Signs and symptoms
Spina bifida occurs in three forms, each varying in severity:
The mildest form of the condition — spina bifida
occulta — results in a small separation or gap in one or more of the
vertebrae of the spine. This can occur in any vertebra but is most
common at the base of the back or lower spine. Because the spinal
nerves aren't involved, most children with this form of spina bifida
have no signs or symptoms and experience no neurologic problems. An
abnormal tuft of hair, a collection of fat, a small dimple or a
birthmark may be seen on the newborn's skin above the spinal defect
and may be the only indication of the condition. In fact, most
people who have spina bifida occulta don't even know it, unless the
condition is discovered during an X-ray for unrelated reasons.
In this rare form of spina bifida, the protective membranes around
the spinal cord (meninges) push out through the opening in the
vertebrae. Because the spinal cord develops normally, these
membranes can be removed by surgery with little or no damage to
Also known as open
spina bifida, myelomeningocele is the most severe form of the
condition — and the form people usually mean when they use the term
spina bifida. In myelomeningocele, the baby's spinal canal
remains open along several vertebrae in the lower or middle back.
Because of this opening, both the membranes and the spinal cord
protrude at birth, forming a sac on the baby's back. In some cases,
skin covers the sac. But in other cases, tissues and nerves are
exposed, making the baby prone to life-threatening infections.
Neurologic impairment below the sac — often including either partial
or complete loss of movement (paralysis) — is common. So are bowel
and bladder problems, seizures and other medical complications.
Doctors aren't certain why neural tubes don't develop or close properly
in some babies. But there seems to be a combination of genetic and
environmental factors that may cause spina bifida. These include:
Spina bifida seems to run in some families. However, 95 percent of
babies with spina bifida are born to parents with no known family
history of the condition.
This vitamin is important to the healthy development
of a fetus. Lack of folic acid increases the risk of spina bifida
and other neural tube defects.
Some researchers believe that a viral infection early
in pregnancy may trigger spina bifida.
Anti-seizure medications, such as valproic acid (Depakene), seem to
cause neural tube defects when taken during pregnancy, perhaps
because they interfere with the body's ability to use folic acid.
Although doctors and researchers don't know for sure why spina bifida
occurs, they have identified a few risk factors:
bifida is more common among Hispanics and whites of European
of neural tube defects.
Couples who've had
one child with a neural tube defect have a one in 40 chance of
having another baby with the same defect. That risk increases to one
in 20 if two previous children have been affected by the condition.
In addition, a woman who was born with a neural tube defect, or has
a close relative with one, has a greater chance of giving birth to a
child with spina bifida. Still, 95 percent of babies with spina
bifida are born to parents with no known family history of this
The risk of spina bifida increases with diabetes, especially
when the mother's blood sugar is elevated early in her pregnancy.
Much of this risk is preventable by careful blood sugar control and
Obese women may have more babies with spina
bifida because of nutritional deficits from poor eating habits or
because they also have diabetes — another known risk factor for
neural tube defects.
When to seek medical advice
If you're a woman of childbearing age, talk to your doctor about taking
a daily multivitamin containing 400 micrograms (mcg) of the B vitamin
folic acid. Up to 70 percent of neural tube defects in the United
States, including spina bifida, could be prevented if all women took
enough folic acid every day before and during early pregnancy.
If you have known risk factors for spina bifida, talk with your doctor
to determine if you should take a larger dose of prescription folic
acid, even before a pregnancy begins. Also discuss which prenatal
screening tests might be warranted for you.
If your baby is born with myelomeningocele, you'll likely need to
consult with a multidisciplinary team of physicians, surgeons and
therapists at a center that specializes in spina bifida treatment.
Children with myelomeningocele may require ongoing medical attention
throughout their lives to monitor their condition and treat
Spina bifida >