Now Know All about Anencephaly: Cause, Symptoms, Diagnosis, Treatment

Anencephaly is a serious and rare birth defect in which a baby is born without parts of the brain and skull. This neural tube defect occurs early in pregnancy, usually in the first month, and is one of the most severe congenital anomalies. Babies born with anencephaly typically lack the forebrain, the largest part of the brain responsible for cognition, and are missing portions of the skull and scalp. This condition is almost always fatal, with most affected infants being stillborn or dying shortly after birth. (Source)

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What is Anencephaly?

Anencephaly is classified as a neural tube defect (NTD), a group of birth defects that affect the development of the brain and spinal cord. In normal fetal development, the neural tube forms and closes within the first few weeks of pregnancy. In babies with anencephaly, the upper part of the neural tube fails to close properly, resulting in the absence of major portions of the brain, skull, and scalp.

Babies with anencephaly are missing significant parts of their cerebrum, which controls essential functions such as thinking, seeing, hearing, and moving. Without these critical brain structures, survival is impossible. (Source)

How is Anencephaly Caused?

Anencephaly is caused by a failure in the normal closure of the neural tube during embryonic development. This failure can be influenced by a combination of genetic, environmental, and nutritional factors.

• Genetic factors: While no single gene has been identified as the cause, certain genetic mutations or family history of neural tube defects may increase the risk.
• Nutritional factors: A deficiency in folic acid (vitamin B9) during pregnancy is one of the most well-established risk factors for anencephaly and other neural tube defects.
• Environmental factors: Exposure to certain environmental substances, such as certain medications, drugs, or toxic chemicals, can also interfere with neural tube development.

The exact mechanism by which these factors lead to the failure of the neural tube to close is still under investigation, but they all interfere with normal embryonic development. (Source)

History and Science of Anencephaly

Anencephaly has been documented for centuries, with historical cases appearing in ancient medical texts. Advances in the understanding of neural tube defects began in the 20th century, when scientists linked folic acid deficiency to NTDs, including anencephaly.

• Scientific understanding: During early embryogenesis, the neural plate forms, folds, and eventually closes to create the neural tube, which later becomes the brain and spinal cord. When the neural tube fails to close properly at the cranial end, it leads to anencephaly.
• Folic acid and prevention: Research in the 1980s and 1990s revealed that taking folic acid before conception and during early pregnancy significantly reduces the risk of anencephaly. As a result, many countries introduced folic acid fortification in food products to reduce the incidence of neural tube defects. (Source)

Risk Factors for Anencephaly

Several factors can increase the risk of anencephaly in a pregnancy:

1. Folic acid deficiency: A lack of folic acid during early pregnancy is the leading preventable risk factor for anencephaly.
2. Family history: If a family has a history of neural tube defects, including anencephaly, the risk for future pregnancies may be higher.
3. Maternal health conditions: Women with diabetes or those who are obese are at increased risk of having a baby with anencephaly.
4. Medications: Certain medications, such as antiseizure drugs (e.g., valproic acid), may increase the risk of neural tube defects.
5. Environmental exposures: Exposure to harmful chemicals, high heat (like fevers or hot tub use), or certain toxins during early pregnancy can interfere with fetal development. (Source)

Treatment for Anencephaly

There is no treatment or cure for anencephaly. Babies born with this condition usually do not survive long after birth. Most babies with anencephaly are stillborn, and those born alive typically survive only a few hours to a few days due to the severe lack of brain function. Medical care is typically focused on providing comfort to the baby and support to the family.

Prenatal diagnosis of anencephaly allows parents to prepare for the outcome, and some parents may choose to continue the pregnancy to spend time with their baby after birth, even if survival is very short. (Source)

Can Anencephaly Be Prevented?

While anencephaly cannot be completely prevented, there are steps that can significantly reduce the risk:

1. Folic acid supplementation: Women who are planning to become pregnant or who are in the early stages of pregnancy should take 400-800 micrograms (mcg) of folic acid daily. Folic acid supplementation before conception and during early pregnancy has been shown to reduce the risk of neural tube defects by up to 70%.
   • Food fortification: Many countries, including the United States and Canada, have fortified certain foods (such as cereals and bread) with folic acid to reduce the incidence of NTDs in the population.
2. Prenatal care: Regular prenatal check-ups help monitor fetal development and can provide guidance on proper nutrition and health during pregnancy.
3. Avoid harmful substances: Pregnant women should avoid exposure to harmful chemicals, certain medications, smoking, and alcohol during pregnancy to minimize the risk of birth defects.
4. Manage pre-existing conditions: Women with pre-existing health conditions, such as diabetes, should work closely with their healthcare provider to manage their health before and during pregnancy. (Source)

Is Anencephaly Hereditary?

it is not directly inherited in a traditional Mendelian pattern, but genetic factors can play a role. Families with a history of neural tube defects, including anencephaly, may have an increased risk in future pregnancies. However, the risk is still considered relatively low, especially with proper folic acid supplementation. Genetic counseling is recommended for families with a history of NTDs. (Source)

Can Anencephaly Be Cured?

Unfortunately, there is no cure for it. The condition is fatal due to the absence of essential brain structures needed for life. Medical care is focused on providing comfort to the newborn and supporting the family during the grieving process.

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Conclusion

It is a devastating neural tube defect that results in the absence of major portions of the brain and skull. While its exact cause is not fully understood, genetic and environmental factors, particularly folic acid deficiency, play significant roles in its development. Preventive measures, such as folic acid supplementation, have proven effective in reducing the incidence of this condition. Although there is no treatment or cure for anencephaly, early diagnosis and prenatal care provide families with the opportunity to make informed decisions and prepare for the outcome.