What is anencephaly?
Anencephaly is rare neurological disorder that involves 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:
- 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 prognosis for babies born with anencephaly is extremely poor. If the infant is not stillborn, it will usually die within a few hours or days after birth.
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 are also involved.
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.
How can I or my loved one help improve care for people with anencephaly?
Consider participating in a clinical trial so clinicians and scientists can learn more about anencephaly and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.
All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.
For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with neural tube defects at Clinicaltrials.gov.
Where can I find more information about anencephaly?
The following organizations and resources help families and caregivers of individuals with anencephaly:
Birth Defect Research for Children, Inc.
March of Dimes
National Organization for Rare Disorders (NORD)
Phone: 203-744-0100 or 800-999-6673; 844-259-7178 Spanish
More information is also available: