Typically, the neural tube forms early in pregnancy and it closes by the 28th day after conception. In babies with spina bifida, a portion of the neural tube does not close or develop properly, causing problems in the spinal cord and in the bones of the spine.
Spina bifida can range from mild to severe, depending on the type of defect, size, location and complications. When necessary, early treatment for spina bifida involves surgery — although such treatment does not always completely resolve the problem.
Doctors are not certain what causes spina bifida. It is thought to result from a combination of genetic, nutritional and environmental risk factors, such as a family history of neural tube defects and folate (vitamin B-9) deficiency.
Spina bifida is more common among white people and Hispanics, and females are affected more often than males. Although doctors and researchers do not know for sure why spina bifida occurs, they have identified some risk factors:
- Folate deficiency. Folate, the natural form of vitamin B-9, is important to the development of a healthy baby. 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.
- Family history of neural tube defects. Couples who have 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, women who were born with a neural tube defect have a greater chance of giving birth to a child with spina bifida than someone who does not have a neural tube defect. However, most babies with spina bifida are born to parents with no known family history of the condition.
- Some medications. For example, anti-seizure medications, such as valproic acid seem to cause neural tube defects when taken during pregnancy. This might happen because they interfere with the bodys ability to use folate and folic acid.
- Diabetes. Women with diabetes who do not have well-controlled blood sugar 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. Increases in core body temperature, due to fever or use of a sauna or hot tub, have been associated with a slightly 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. If you plan ahead, some medications can be adjusted to diminish the potential risk of spina bifida.
Complications
Spina bifida may cause minimal symptoms or minor physical problems. But severe spina bifida can lead to more significant physical conditions. Severity is affected by:
The size and location of the neural tube defect
Whether skin covers the affected area
Which spinal nerves come out of the affected area of the spinal cord
This list of possible complications may seem overwhelming, but not all children with spina bifida get all of these complications. Many of these complications can be treated.
- Walking and mobility problems. The nerves that control the leg muscles do not work properly below the area of the spina bifida defect. This can cause muscle weakness of the legs and sometimes paralysis. Whether a child can walk typically depends on where the defect is, its size, and the care received before and after birth.
- Orthopedic complications. Children with myelomeningocele can have a variety of problems in the legs and spine because of weak muscles in the legs and back. The types of problems depend on the location of the defect. Possible problems include orthopedic issues such as:
- Curved spine (scoliosis)
- Abnormal growth
- Dislocation of the hip
- Bone and joint deformities
- Muscle contractures
- Bowel and bladder problems. Nerves that supply the bladder and bowels usually do not work properly when children have myelomeningocele. This is because the nerves that supply the bowel and bladder come from the lowest level of the spinal cord.
- Accumulation of fluid in the brain (hydrocephalus). Babies born with myelomeningocele commonly experience accumulation of fluid in the brain, a condition known as hydrocephalus.
- Shunt malfunction. Shunts placed in the brain to treat hydrocephalus can stop working or become infected. Warning signs may vary. Some of the warning signs of a shunt that is not working include:
- Headaches
- Vomiting
- Sleepiness
- Irritability
- Swelling or redness along the shunt
- Confusion
- Changes in the eyes (fixed downward gaze)
- Trouble feeding
- Seizures
- Chiari malformation type II. Chiari malformation (kee-AH-ree mal-for-MAY-shun) type 2 is a common problem with the brain in children who have the myelomeningocele type of spina bifida. The brainstem is the lowest part of the brain above the spinal cord. In Chiari malformation type 2, the brainstem is elongated and positioned lower than usual. This can cause problems with breathing and swallowing. Rarely, compression on this area of the brain occurs and surgery is needed to relieve the pressure.
- Infection in the tissues surrounding the brain (meningitis). Some babies with myelomeningocele may develop meningitis, an infection in the tissues surrounding the brain. This potentially life-threatening infection may cause brain injury.
- Tethered spinal cord. Tethered spinal cord results when the spinal nerves bind to the scar where the defect was closed surgically. The spinal cord is less able to grow as the child grows. This progressive tethering can cause loss of muscle function to the legs, bowel or bladder. Surgery can limit the degree of disability.
- Sleep-disordered breathing. Both children and adults with spina bifida, particularly myelomeningocele, may have sleep apnea or other sleep disorders. Assessment for a sleep disorder in those with myelomeningocele helps detect sleep-disordered breathing, such as sleep apnea, which warrants treatment to improve health and quality of life.
- Skin problems. Children with spina bifida may get wounds on their feet, legs, buttocks or back. They can not feel when they get a blister or sore. Sores or blisters can turn into deep wounds or foot infections that are hard to treat. Children with myelomeningocele have a higher risk of wound problems in casts.
- Latex allergy. Children with spina bifida have a higher risk of latex allergy, an allergic reaction to natural rubber or latex products. Latex allergy may cause rash, sneezing, itching, watery eyes and a runny nose. It can also cause anaphylaxis, a potentially life-threatening condition in which swelling of the face and airways can make breathing difficult. So it is best to use latex-free gloves and equipment at delivery time and when caring for a child with spina bifida.
- Other complications. More problems may arise as children with spina bifida get older, such as urinary tract infections, gastrointestinal (GI) disorders and depression. Children with myelomeningocele may develop learning disorders, such as problems paying attention, and difficulty learning reading and math.
- Prevention
- Folic acid, taken in supplement form starting at least one month before conception and continuing through the first trimester of pregnancy, greatly reduces the risk of spina bifida and other neural tube defects.
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- Get folic acid first
- Having enough folic acid in your system by the early weeks of pregnancy is critical to prevent spina bifida. Because many women do not discover that they are 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 are fortified with 400 mcg of folic acid per serving, including:
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- Enriched bread
- Pasta
- Rice
- Some breakfast cereals
- Folic acid may be listed on food packages as folate, which is the natural form of folic acid found in foods.
