What is Spina Bifida?
Spina Bifida is a birth defect involving incomplete formation of the spine.
Seven out of every 10,000 births in the United States is a baby with Spina
Bifida. This amounts to about 8 babies born each day with Spina Bifida. Spina
Bifida occurs within the first month of pregnancy – before most women know they
are pregnant.
What Causes Spina Bifida?
The exact cause of Spina Bifida is unknown. It is believed both genetic factors
(one or more genes) and environmental factors interact to cause Spina Bifida.
Therefore, it is possible individuals inherit multiple genes that make them
susceptible to having Spina Bifida, but something in the environment triggers
the Spina Bifida to develop.
How Can Spina Bifida Be Prevented?
While there is no guaranteed method of preventing a baby from having a birth
defect, there are methods to reduce the risk. Studies show that folic acid, a
water-soluble B-vitamin, can reduce the chance of a baby having Spina Bifida by
up to 75% when a woman takes it prior to becoming pregnant and through the first
trimester. Therefore, it is recommended that all women of childbearing age
consume 0.4 milligrams (400 micrograms) of folic acid each day, especially one
month prior to becoming pregnant and through the first trimester. Women who have
already had a pregnancy with Spina Bifida are advised to take an even larger
dose of folic acid; they should take 4.0 milligrams every day. The 4.0
milligrams of folic acid should only be obtained through a prescription and
should be taken under a physician's supervision. This high dosage should not be
obtained by increasing the dosage of a multivitamin containing folic acid
because high levels of other vitamins can be harmful. However, some women,
despite active diet supplementation with folic acid, can still have a baby with
Spina Bifida. Folic acid does not prevent all cases of Spina Bifida.
Who is at Risk for having a Baby with Spina Bifida?
There are approximately 65 million women of childbearing age in the United
States. Any woman who is capable of becoming pregnant can have a baby with Spina
Bifida. It is currently not possible to predict which women will have a baby
with Spina Bifida. Ninety-five percent of individuals with Spina Bifida have no
personal or family history of Spina Bifida.
Are there Factors That Increase the Chance of Having a Pregnancy with
Spina Bifida?
Yes. Many factors affect the outcome of a pregnancy, including genetics,
environmental factors, and certain illnesses or medications. These include:
A previous pregnancy with Spina Bifida (This increases a woman's chance of
having a subsequent affected pregnancy by 20-50 times.)
Family history of Spina Bifida in another relative, even distantly related,
such as sibling, parent, aunt/uncle, grandparent, cousin, etc.
Maternal insulin-dependent diabetes
Maternal use of certain anti-seizure medications
Medically diagnosed obesity in the mother
Race/ethnicity (Spina Bifida is more prevalent among Caucasian individuals
than African-Americans and more common among Hispanics than non-Hispanics)
Some other factors that may increase a woman's chance of having a
baby with Spina Bifida, but that are not as well characterized, include:
Exposure to high temperatures in early pregnancy (i.e. prolonged high fevers
and extended hot tub or sauna use)
Agent Orange exposure in the father
Can Genetic
Research Help?
The scientific community does recognize that a genetic link exists. Researchers
are currently trying to identify the specific gene(s) that contribute to the
development of Spina Bifida. It is hoped these discoveries will eventually lead
to a better understanding of how Spina Bifida develops so that better
treatments, or even a cure, will be available. Genetic discoveries may also lead
to future genetic tests to determine an individual's or couple's chance for
having a baby with Spina Bifida.
Should I Speak with a Genetic Counselor?
For more information about your personal chance for having a baby with Spina
Bifida or other neural tube defect, please speak with a genetic counselor. A
genetic counselor can suggest appropriate tests, explain test procedures and
results, present your options, and answer any questions.
How Can I Find a Genetic Counselor?
To find a genetic counselor in your area, please contact the National Society of
Genetics Counselors:
This information does not constitute medical advice for any individual. As
specific cases may vary from the general information presented here, SBAGNO
advises readers to consult a qualified medical or other professional on an
individual basis.