Can all neural tube defects be prevented?

Neural tube defects (NTDs) are birth defects that occur in the brain, spinal cord, or spine of a developing fetus. These defects form in the first month of pregnancy, often before a woman knows she is pregnant. Common examples of these defects include spina bifida and anencephaly. Although some neural tube defects can be prevented, not all cases can be fully prevented.

Proper nutrition and early screenings play a vital role in reducing the risks of these defects, but some cases may occur due to unknown reasons or factors beyond direct control. It is important to consult with a specialist physician for comprehensive guidance on prevention and care.

What are neural tube defects?

The neural tube forms very early in fetal development, later becoming the spinal cord, brain, and the protective structures surrounding them, including the spine. A neural tube defect occurs when this tube fails to close completely somewhere along its length, resulting in a gap in the spine or another issue. These deformities usually occur between the third and fourth week of pregnancy [3]. The most prominent types of neural tube defects are:

• Spina Bifida: This is the most common type and occurs when the neural tube does not close completely. Its severity can range from mild (spina bifida occulta), where it causes no disability, to severe (myelomeningocele), which causes partial or total paralysis and problems with bladder and bowel function [1].
• Anencephaly: A more serious but less common condition that occurs when the neural tube fails to close at the top, leading to the absence of most or all of the brain; the skull may also lack parts. Infants born with this condition are usually unconscious and pass away shortly after birth [1].
• Encephalocele: Another rare type that occurs when the tube fails to close near the brain, leading to the brain and the membranes covering it protruding through an opening in the skull [1].

Preventing neural tube defects

Not all neural tube defects can be prevented, but there are steps that can be taken to significantly reduce the risks. The most important of these steps is taking folic acid. It is recommended to take folic acid supplements before pregnancy and during the first months of it. Women of childbearing age should take 400 micrograms of folic acid daily, even if they are not planning to get pregnant, because neural tube defects form very early in pregnancy [1].

Additionally, some factors can increase the risk of these defects, such as a family history of birth defects, having diabetes, or using certain medications during pregnancy. In these cases, a doctor may recommend higher doses of folic acid or additional tests.

Screenings during pregnancy

Although prevention is the first step, regular screenings during pregnancy help in the early detection of any potential deformities. One such screening is the Alpha-fetoprotein (AFP) test. This test is a blood test that measures the level of alpha-fetoprotein in the pregnant woman's blood and is usually performed between the 15th and 20th week of pregnancy [2]. Abnormal levels of AFP may indicate an increased risk of the fetus having a neural tube defect, such as spina bifida or anencephaly [2].

It is important to note that the AFP test does not definitively diagnose the condition, but rather points to an increased likelihood of a problem. If the results are abnormal, additional tests such as a detailed ultrasound or amniocentesis will be performed to confirm the diagnosis [2]. You can learn more about this topic by visiting Neural tube defects: pre-conception screening, prevention, and management (Arabic).

Managing detected cases

If a neural tube defect is diagnosed, the management of the case depends on the type and severity of the defect. In some cases, there may be surgical options before or after birth to improve outcomes. For example, surgery can be performed to repair spina bifida in some cases. Multidisciplinary support, which includes neurologists, surgeons, physical therapists, and occupational therapists, is essential to provide the best care for the affected child [1].

It is important for parents to receive psychological support and comprehensive information to help them understand the condition and make appropriate decisions regarding the care of their child. Always consult the healthcare team for accurate and personalized information for the case.

Medical references

• About Neural Tube Defects (NTDs)
• Alpha-Fetoprotein (AFP) Test
• Birth Disorders of the Brain and Spinal Cord