What Is Anencephaly?
Anencephaly is a defect in the closure of the
neural tube during fetal development. The neural tube is a narrow channel that
folds and closes between the third and fourth weeks of pregnancy to form the
brain and spinal cord of the embryo. Anencephaly occurs when the "cephalic" or
head end of the neural tube fails to close, resulting in the absence of a major
portion of the brain, skull and scalp. Infants with this disorder are born
without a forebrain (the front part of the brain) and a cerebrum (the thinking
and coordinating part of the brain). The remaining brain tissue is often exposed
— not covered by bone or skin. A baby born with anencephaly is usually blind,
deaf, unconscious and unable to feel pain. Although some individuals with
anencephaly may be born with a rudimentary brain stem, the lack of a functioning
cerebrum permanently rules out the possibility of ever gaining consciousness.
Reflex actions such as breathing and responses to sound or touch may
occur.
The cause of anencephaly is unknown. Although it is thought that a
mother's diet and vitamin intake may play a role, scientists believe that many
other factors also are involved.
Recent studies have shown that the
addition of folic acid (vitamin B9) to the diet of women of childbearing age may
significantly reduce the incidence of neural tube defects. Therefore it is
recommended that all women of childbearing age consume 0.4 mg of folic acid
daily.
Is There Any Treatment?
There is no cure or standard
treatment for anencephaly. Treatment is supportive.
What Is the
Prognosis?
The prognosis for babies born with anencephaly is
extremely poor. If the infant is not stillborn, then he or she will usually die
within a few hours or days after birth.
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