Spina Bifida

Doctors aren't certain what causes spina bifida. As with many other problems, it appears to result from a combination of genetic and environmental risk factors, such as a family history of neural tube defects and folic acid deficiency.

Risk factors

Although doctors and researchers don't know for sure why spina bifida occurs, they have identified a few risk factors:

Race - Spina bifida is more common among whites and Hispanics.

Family history of neural tube defects - Couples who've had one child with a neural tube defect have a slightly higher chance of having another baby with the same defect. That risk increases if two previous children have been affected by the condition. In addition, a woman who was born with a neural tube defect, or who has a close relative with one, has a greater chance of giving birth to a child with spina bifida. However, most babies with spina bifida are born to parents with no known family history of the condition.

Folate deficiency - Folate (vitamin B-9) is important to the healthy development of a baby. Folate is the natural form of vitamin B-9. The synthetic form, found in supplements and fortified foods, is called folic acid. A folate deficiency increases the risk of spina bifida and other neural tube defects.

Some medications - Anti-seizure medications, such as valproic acid (Depakene, Stavzor), seem to cause neural tube defects when taken during pregnancy, perhaps because they interfere with the body's ability to use folate and folic acid.

Diabetes - Women with diabetes who don't control their blood sugar well have a higher risk of having a baby with spina bifida.

Obesity - Pre-pregnancy obesity is associated with an increased risk of neural tube birth defects, including spina bifida.
Increased body temperature. Some evidence suggests that increased body temperature (hyperthermia) in the early weeks of pregnancy may increase the risk of spina bifida. Elevating your core body temperature due to fever or the use of saunas or hot tubs, has been associated with increased risk of spina bifida.

If you have known risk factors for spina bifida, talk with your doctor to determine if you need a larger dose or prescription dose of folic acid, even before a pregnancy begins. If you take medications, tell your doctor. Some medications can be adjusted to diminish the potential risk of spina bifida, if plans are made ahead of time.

If you're pregnant, you'll be offered prenatal screening tests to check for spina bifida and other birth defects. The tests aren't perfect. Most mothers who have positive blood tests have normal babies. Also, even if the results are negative, there's still a small chance that spina bifida is present. Talk to your doctor about prenatal testing, its risks and how you might handle the results.

Blood tests
Your doctor will most likely check for spina bifida by first performing the following:

Maternal serum alpha-fetoprotein (MSAFP) test - A common test used to check for myelomeningocele is the maternal serum alpha-fetoprotein (MSAFP) test. To perform this test, your doctor draws a blood sample and sends it to a laboratory, where it's tested for alpha-fetoprotein (AFP) — a protein that's produced by the baby. It's normal for a small amount of AFP to cross the placenta and enter the mother's bloodstream, but abnormally high levels of AFP suggest that the baby has a neural tube defect, most commonly spina bifida or anencephaly, a condition characterized by an underdeveloped brain and an incomplete skull.

Some spina bifida cases don't produce a high level of AFP. On the other hand, when a high level of AFP is found, a neural tube defect is present only a small percentage of the time. Varying levels of AFP can be caused by other factors — including a miscalculation in fetal age or multiple babies — so your doctor may order a follow-up blood test for confirmation. If the results are still high, you'll need further evaluation, including an ultrasound examination.

Other blood tests - Your doctor may perform the MSAFP test with two or three other blood tests, which may detect other hormones, such as human chorionic gonadotropin (HCG), inhibin A and estriol. Depending on the number of tests, the combination is called a triple screen or quadruple screen (quad screen). These tests are commonly done with the MSAFP test, but their objective is to screen for trisomy 21 (Down syndrome), not neural tube defects.

Ultrasound
Many obstetricians rely on ultrasonography to screen for spina bifida. If blood tests indicate high AFP levels, your doctor will suggest an ultrasound exam to help determine why. The most common ultrasound exams bounce high-frequency sound waves off tissues in your body to form black-and-white images on a video monitor.

The information these images provide can help establish whether there's more than one baby and can help confirm gestational age, two factors that can affect AFP levels. An advanced ultrasound can also detect signs of spina bifida, such as an open spine or particular features in your baby's brain that indicate spina bifida.

In expert hands, ultrasound today is quite effective in detecting spina bifida and assessing its severity. Ultrasound is safe for both mother and baby.

Amniocentesis
If a blood test shows high levels of AFP in your blood but the ultrasound is normal, your doctor may offer amniocentesis. During amniocentesis, your doctor uses a needle to remove a sample of fluid from the amniotic sac that surrounds the baby. An analysis indicates the level of AFP present in the amniotic fluid.

A small amount of AFP is normally found in amniotic fluid. However, when an open neural tube defect is present, the amniotic fluid contains an elevated amount of AFP because the skin surrounding the baby's spine is gone and AFP leaks into the amniotic sac. A second test can be done on the same sample to reliably confirm that a neural tube defect is present.

Discuss the risks of this test, including a slight risk of loss of the pregnancy, with your doctor.

News that your newborn child has a condition such as spina bifida can naturally cause you as a parent to feel grief, anger, frustration, fear and sadness. There's good reason to hope, however, because most people with spina bifida live active, productive and full lives — especially with encouragement and support from loved ones.

Even with severe spina bifida, most children can walk for at least short distances, usually with the assistance of braces, canes or crutches, although they may require wheelchairs for longer distances. Using these devices can help a child compensate for his or her condition and gain more independence.

Many children with spina bifida have normal intelligence, but they may need early educational intervention for learning problems. They may also need extra help from teachers and counselors to adapt to school. A physical disability like spina bifida can also cause emotional and social problems. Children with spina bifida need encouragement to participate in activities with their peers and to lead independent lives, within their physical limitations and capabilities. It may be helpful to remember that these children have never known what's accepted as normal function and often adapt to their condition in remarkable ways.

If your child has spina bifida, you may benefit from finding a support group of other parents who are dealing with the condition. Talking with others who understand the challenges — and rewards — of living with spina bifida can be helpful.

Folic acid, taken in supplement form at least one month before conception and during the first trimester of pregnancy, greatly reduces the risk of spina bifida and other neural tube defects.

Get folic acid first
It's critical to have enough folic acid in your system by the early weeks of pregnancy to prevent spina bifida. Because many women don't discover that they're pregnant until this time, experts recommend that all women of childbearing age take a daily supplement of 400 micrograms (mcg) of folic acid. Several foods, including bread, pasta, rice and breakfast cereals, are fortified with 400 mcg of folic acid per serving. Folic acid may be listed on food packages as folate, which is the natural form of folic acid found in food.

Planning pregnancy
If you're actively trying to conceive, most pregnancy experts believe supplementation of at least 400 mcg of folic acid a day is the best approach for women planning pregnancy. Your body doesn't absorb folate as easily as it absorbs synthetic folic acid, and most people don't get the recommended amount of folate through diet alone, so vitamin supplements are necessary to prevent spina bifida. And, it's possible that folic acid will also help reduce the risk of other birth defects, including cleft lip, cleft palate and some congenital heart defects.

It's also a good idea to eat a healthy diet, including foods rich in folate or enriched with folic acid. This vitamin is present naturally in many foods, including:

- Beans
- Citrus fruits and juices
- Egg yolks
-Dark green vegetables, such as broccoli and spinach

When higher doses are needed
If you have spina bifida or if you've given birth to a child with spina bifida, you'll need extra folic acid before you become pregnant. If you're taking anti-seizure medications or you have diabetes, you may also benefit from a higher dose of this B vitamin. In these cases, the recommended dose of folic acid may be up to 4,000 mcg (4 mg) beginning one month prior to conception and during the first few months of pregnancy. However, check with your doctor before taking additional folic acid supplements.

All information sourced from - MayoClinic.com Spina Bifida Information.