Neural Tube Defects (NTDs) are a group of birth defects that affect the brain, spine, or spinal cord. They occur during early fetal development—usually within the first month of pregnancy—when the neural tube, which eventually forms the baby’s central nervous system, fails to close completely. These defects can lead to lifelong disabilities or, in severe cases, be life-threatening.

The most common types of neural tube defects in children include spina bifida, anencephaly, and encephalocele. These conditions can range from mild to severe, depending on the size and location of the defect. Spina bifida, the most recognized form, occurs when the spinal cord doesn’t develop properly, potentially causing paralysis, mobility issues, or bladder problems.

Neural tube defects in babies are among the most preventable congenital anomalies. Adequate intake of folic acid before and during early pregnancy can significantly reduce the risk. However, NTDs still occur globally, especially in regions where maternal nutrition and prenatal care are lacking. Early diagnosis, either prenatally or at birth, helps in planning appropriate treatment strategies that can improve the quality of life for affected children.

What Causes Neural Tube Defects in Children?

The exact cause of neural tube defects in children is multifactorial, involving genetic, environmental, and nutritional influences. It is important to understand these risk factors so that timely preventive strategies can be implemented.

1. Folic Acid Deficiency

Perhaps the most well-established cause of NTDs is a deficiency of folic acid (vitamin B9). Folic acid is crucial for DNA synthesis and cell division during fetal development. Women who don’t consume adequate folate during early pregnancy—or even before conception—are at a significantly higher risk of having a baby with an NTD.

2. Genetic and Family History

A family history of neural tube defects, especially in siblings, increases the likelihood of recurrence. Certain genetic mutations that affect folate metabolism may also contribute to the condition.

3. Maternal Health Conditions

Some maternal conditions such as:

• Diabetes
• Obesity
• Hyperthermia (high fever or hot tub use during early pregnancy)
• Certain infections

have been associated with a higher risk of NTDs in the fetus.

4. Medications and Environmental Toxins

Drugs like valproic acid (used for epilepsy or bipolar disorder) and methotrexate can interfere with folic acid metabolism. Exposure to environmental toxins or pollutants during pregnancy may also increase the risk.

5. Socioeconomic and Nutritional Factors

Low socioeconomic status is often linked with poor maternal nutrition, lack of prenatal vitamins, and limited access to healthcare, which together contribute to a higher incidence of neural tube defects in newborns.

Types and Symptoms of Neural Tube Defects

Different types of NTDs present with varied symptoms depending on which part of the neural tube is affected. Early diagnosis is essential for initiating the right course of treatment.

1. Spina Bifida

This is the most common and treatable form of neural tube defect in children. It occurs when the spine and spinal cord don’t form properly.

Types include:

• Spina bifida occulta (mildest): Often asymptomatic, sometimes identified by a dimple or hair tuft on the back.
• Meningocele: A sac of fluid protrudes through an opening in the spine, usually without spinal cord involvement.
• Myelomeningocele (most severe): The spinal cord and nerves protrude through an opening, often leading to paralysis, bowel/bladder dysfunction, and hydrocephalus.

2. Anencephaly

A severe and fatal defect where parts of the brain and skull do not form. Infants are often stillborn or die shortly after birth.

3. Encephalocele

A sac-like protrusion of the brain and membranes through a skull defect. Symptoms vary but may include seizures, developmental delays, and vision problems.

How Are Neural Tube Defects Diagnosed?

Prenatal Diagnosis

NTDs can often be detected during pregnancy through routine screening and diagnostic tests:

• Maternal serum alpha-fetoprotein (MSAFP) test around 16–18 weeks.
• Ultrasound imaging, especially high-resolution or targeted ultrasound.
• Amniocentesis to assess AFP levels and chromosomal abnormalities.

Postnatal Diagnosis

If not diagnosed prenatally, NTDs are often obvious at birth, especially in the case of spina bifida or encephalocele. In such cases, MRI or CT scans help in evaluating the extent of neurological involvement.

Early detection allows for appropriate counseling, planning for delivery at a tertiary center, and timely postnatal surgical or medical intervention.

Treatment Options for Neural Tube Defects

Treatment depends on the type and severity of the neural tube defect and the child’s overall health.

1. Spina Bifida

• Surgical closure of the defect within 24–48 hours after birth helps reduce infection risk and protects the exposed nerves.
• Shunt placement may be required to treat hydrocephalus, which is common in myelomeningocele.
• Rehabilitation: Physical therapy, orthopedic support, and sometimes bladder/bowel management programs are essential for long-term care.

2. Anencephaly

There is no treatment for anencephaly. Palliative care is provided, and supportive counseling is crucial for the family.

3. Encephalocele

Surgical repair is usually performed, followed by therapy to manage developmental or neurological issues depending on brain involvement.

Table: Types of Neural Tube Defects and Key Features

Preventing Neural Tube Defects in Children

1. Folic Acid Supplementation

The most effective preventive measure is adequate folic acid intake before conception and during early pregnancy. The WHO recommends:

• 400 micrograms of folic acid daily for all women of childbearing age.
• 4 mg/day for women with a previous NTD-affected pregnancy.

2. Managing Maternal Health

Controlling diabetes and obesity, avoiding harmful medications, and managing fever or infections during early pregnancy can help reduce the risk.

3. Genetic Counseling

Families with a history of NTDs may benefit from genetic counseling and risk assessment before planning another pregnancy.

4. Fortified Foods

Many countries now fortify staple foods like flour and cereals with folic acid, which has led to a significant decline in neural tube defects globally.

Frequently Asked Questions (FAQs)

Can neural tube defects be detected before birth?
Yes, many neural tube defects, especially spina bifida and anencephaly, can be detected during pregnancy using maternal blood tests and ultrasounds. The maternal serum alpha-fetoprotein (MSAFP) test, usually done between 16 and 18 weeks, screens for NTDs. High levels may indicate a defect, which is then confirmed with detailed ultrasounds or amniocentesis. Early diagnosis enables better planning, including referrals to high-risk pregnancy centers and preparation for surgery or palliative care if necessary.

How much folic acid should women take to prevent NTDs?
To prevent neural tube defects, women of reproductive age should take at least 400 micrograms (mcg) of folic acid daily, starting at least one month before conception and continuing through the first trimester. For women who have had a previous pregnancy affected by NTDs, the recommended dose is much higher—4 milligrams (mg) per day—under a doctor’s supervision. Folic acid can be obtained through supplements and fortified foods, but natural food sources like leafy greens, citrus fruits, and legumes may not provide sufficient levels alone.

Are neural tube defects hereditary?
Neural tube defects can have a genetic component, though they are not typically inherited in a straightforward Mendelian fashion. A family history of NTDs, especially in siblings, increases the risk in subsequent pregnancies. Certain gene mutations that interfere with folate metabolism have been associated with increased susceptibility. However, environmental factors like folate deficiency, maternal diabetes, or exposure to medications also play a significant role.

What is the difference between spina bifida and anencephaly?
Spina bifida is a neural tube defect where the spinal cord and surrounding structures do not develop properly, leading to possible physical and neurological impairments. It can range from mild (spina bifida occulta) to severe (myelomeningocele). Anencephaly, on the other hand, is a much more severe defect where major parts of the brain and skull are missing. Babies with anencephaly are usually stillborn or die shortly after birth, while many children with spina bifida can survive with proper medical support.

Can children with neural tube defects lead a normal life?
It depends on the severity of the condition. Children with mild forms of spina bifida often lead fairly normal lives with little to no impairment. Those with more severe forms may need ongoing physical therapy, assistive devices, and medical interventions. With advancements in neurosurgery and rehabilitation, the quality of life for these children has greatly improved. Supportive schooling, mobility aids, and specialized care plans allow many to attend school, participate in activities, and develop socially and emotionally.

How is spina bifida treated after birth?
Spina bifida treatment usually begins within the first 48 hours after birth with surgical closure of the spinal defect to prevent infection and further nerve damage. Babies with hydrocephalus, a common complication, may require a shunt to drain excess fluid from the brain. Long-term management includes physiotherapy, bladder/bowel training, orthopedic surgeries, and regular follow-ups with neurologists and urologists. Early intervention plays a crucial role in improving mobility and independence.

Is there a cure for neural tube defects?
There is currently no cure for neural tube defects. Treatment focuses on managing symptoms, preventing complications, and improving the child’s quality of life. Surgical interventions, rehabilitation therapies, and supportive care can make a significant difference, especially in spina bifida and encephalocele. Anencephaly, being a lethal condition, does not have a treatment and requires palliative care.

What lifestyle changes can reduce the risk of NTDs during pregnancy?
To reduce the risk of neural tube defects, women should focus on prenatal health and nutrition. This includes taking folic acid supplements, maintaining a healthy weight, controlling chronic conditions like diabetes, avoiding alcohol and smoking, and minimizing exposure to harmful medications or environmental toxins. Regular prenatal visits, balanced diet, and prompt treatment of infections or fevers during early pregnancy are also critical.

Do vaccines or medications cause neural tube defects?
No, routine vaccines do not cause neural tube defects. However, certain medications—particularly those that interfere with folate metabolism like valproic acid and carbamazepine—have been linked to a higher risk of NTDs. Women taking such medications for epilepsy or other conditions should consult their doctors about switching to safer alternatives during pregnancy planning. Folic acid supplementation is especially important in these cases.

Can NTDs occur in later stages of pregnancy?
No, neural tube defects occur very early in pregnancy, usually within the first 28 days after conception—often before many women realize they are pregnant. This is why folic acid supplementation should begin preconception. Once the neural tube has closed and the early organs are formed, the risk of NTDs is significantly reduced. Regular prenatal care remains important to detect other anomalies or complications.

Research Articles on Neural Tube Defects in Children