Understanding Neural Tube Defects: Causes, Diagnosis, and Prevention

Highlights

• The neural tube forms early in pregnancy and develops into the brain and spinal cord.
• Neural tube defects occur when the neural tube does not fully close.
• Taking folic acid (vitamin B9) supplements before and during early pregnancy significantly reduces the risk of neural tube defects.
• Ultrasounds and second-trimester maternal serum screening tests can help diagnose neural tube defects.
• If diagnosed, a specialized medical team may offer further tests, counseling, and treatment options.

In This Article

• What Is the Neural Tube
• Understanding Neural Tube Defects
• Contributing Factors and Causes
• Diagnosis and Testing
• When a Neural Tube Defect Is Diagnosed
• Prevention Strategies
• Recommended Folic Acid Intake
• Tools and Assistance

What Is the Neural Tube?

The neural tube forms within the first four weeks of pregnancy, often before a person knows they are pregnant. This structure eventually develops into the baby’s brain and spinal cord. If the neural tube does not close completely, it can lead to neural tube defects, which may affect the baby’s brain, spine, or spinal cord.

Understanding Neural Tube Defects

Neural tube defects occur when the neural tube fails to close properly. The most common types include:

• Anencephaly – A severe birth defect where major parts of the brain, skull, and scalp do not develop properly. Babies with anencephaly often do not survive long after birth.
• Encephalocele – A condition where brain tissue or its membranes bulge through a skull defect.
• Spina bifida – A condition where parts of the spine do not fully close, leading to potential nerve damage and physical disabilities of varying severity.

Contributing Factors and Causes

The exact causes of neural tube defects are not fully understood, but several factors can increase the risk, including:

• A lack of folic acid in the early stages of pregnancy
• Certain medications, such as those used to treat epilepsy
• Diabetes that is insulin-dependent
• A family history of neural tube defects or a previous pregnancy affected by them

Diagnosis and Testing

Neural tube defects are typically diagnosed during the second trimester through the following screening methods:

• Maternal Serum Screening Test – A blood test performed between weeks 14 and 20 of pregnancy to estimate the risk of neural tube defects. If results indicate a higher risk, further diagnostic tests may be recommended.
• Ultrasound Screening – Conducted between weeks 18 and 20 to monitor fetal development and detect most cases of neural tube defects.

In some cases, mild neural tube defects may go undetected until after birth.

When a Neural Tube Defect Is Diagnosed

If a neural tube defect is diagnosed during pregnancy, a specialized medical team will provide additional tests, counseling, and treatment options. The severity of the condition determines the level of medical care and support needed.

Children with neural tube defects may experience:

• Physical disabilities – Difficulty with movement and coordination
• Bladder and bowel challenges – Difficulty controlling bladder and bowel functions
• Hearing and vision impairments
• Intellectual disabilities
• Differences in physical appearance

Families may need to consider various medical interventions, ongoing treatments, and support systems. Healthcare professionals will provide guidance to help parents make informed decisions about pregnancy and potential treatment options.

Prevention Strategies

The risk of neural tube defects can be significantly reduced by ensuring adequate folic acid intake before and during early pregnancy. Studies indicate that folic acid supplements can lower the risk of neural tube defects by up to 70%.

Folic acid is available in supplement form and can be found naturally in foods such as:

• Green leafy vegetables
• Certain fruits
• Legumes (beans, peas, lentils)
• Wholegrain breads
• Fortified cereals

Recommended Folic Acid Intake

The recommended daily intake of folic acid varies based on individual circumstances:

• Adults should consume at least 0.4 mg (400 mcg) daily.
• Pregnant individuals and those planning pregnancy should take an additional 0.4 mg (400 mcg) supplement daily, starting at least one month before conception and continuing through the first trimester.
• High-risk individuals (such as those with a history of neural tube defects) may require a higher dosage of 5 mg daily, as recommended by a healthcare provider.

A doctor or dietitian can help determine the appropriate amount of folic acid based on personal health conditions and family history.

Tools and Assistance

If you are feeling overwhelmed or have concerns during pregnancy, support is available. Helpful tools and resources include:

• Parenting and disability support groups: Peer support can offer a sense of community and shared experience.
• Healthcare professionals: Your doctor, midwife, or a genetic counselor can offer expert guidance and answer any questions.
• Nutritional counseling: Dietitians can provide tailored advice on folic acid intake and prenatal nutrition.
• Prenatal education classes: These programs may include sessions on fetal development, screening options, and managing prenatal health.
• Emotional support services: If you are coping with a diagnosis or concerned about risks, mental health professionals can help you navigate your feelings.

Need more information?

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