Navigate Up

Neurology Center - A-Z Index

#
J
Q
X
Y
Z

Print This Page

Anencephaly

Anencephaly is the absence of a large part of the brain and the skull.

Alternative Names

Aprosencephaly with open cranium

Causes

Anencephaly is one of the most common neural tube defects. Neural tube defects are birth defects that affect the tissue that grows into the spinal cord and brain.

Anencephaly occurs early in the development of an unborn baby. It results when the upper part of the neural tube fails to close. Why this happens is not known. Possible causes include environmental toxins and low intake of folic acid by the mother during pregnancy.

Anencephaly occurs in about 1 out of 10,000 births. The exact number is unknown, because many of these pregnancies result in miscarriage. Having one infant with this condition increases the risk of having another child with neural tube defects.

Symptoms

  • Absence of the skull
  • Absence of the brain (cerebral hemispheres and cerebellum)
  • Facial feature abnormalities
  • Heart defects

Exams and Tests

A pregnancy ultrasound is done to confirm the diagnosis. The ultrasound may reveal too much fluid is in the uterus. This condition is called polyhydramnios .

Other tests that may be done on the pregnant mother:

  • Amniocentesis (to look for increased levels of alpha-fetoprotein )
  • Alpha-fetoprotein level (increased levels suggest a neural tube defect)
  • Urine estriol level

A pre-pregnancy serum folic acid test may also be done.

Treatment

There is no current therapy. Talk to your doctor about care decisions.

Outlook (Prognosis)

This condition usually causes death within a few days.

When to Contact a Medical Professional

A health care provider usually detects this condition during routine prenatal testing and ultrasound. Otherwise, it is recognized at birth.

If anencephaly is detected before birth, further counseling will be needed.

Prevention

It is important for women who may become pregnant to get enough folic acid.

There is good evidence that folic acid can help reduce the risk of certain birth defects, including anencephaly. Women who are pregnant or planning to become pregnant should take a multivitamin with folic acid every day. Many foods are now fortified with folic acid to help prevent these kinds of birth defects.

Getting enough folic acid can reduce the chance of neural tube defects by 50 percent.

For specific recommendations, see folic acid (folate) .

References

Kinsman SL, Johnston MV. Congenital anomalies of the central nervous system. In: Kliegman, RM, Behrman RE, St. Geme JW III, Schor NF, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 585.

Updated: 5/10/2013

Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.


©  UPMC | Affiliated with the University of Pittsburgh Schools of the Health Sciences
Supplemental content provided by A.D.A.M. Health Solutions. All rights reserved.

For help in finding a doctor or health service that suits your needs, call the UPMC Referral Service at 412-647-UPMC (8762) or 1-800-533-UPMC (8762). Select option 1.

UPMC is an equal opportunity employer. UPMC policy prohibits discrimination or harassment on the basis of race, color, religion, ancestry, national origin, age, sex, genetics, sexual orientation, marital status, familial status, disability, veteran status, or any other legally protected group status. Further, UPMC will continue to support and promote equal employment opportunity, human dignity, and racial, ethnic, and cultural diversity. This policy applies to admissions, employment, and access to and treatment in UPMC programs and activities. This commitment is made by UPMC in accordance with federal, state, and/or local laws and regulations.

Medical information made available on UPMC.com is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have. Further, UPMC.com is not a tool to be used in the case of an emergency. If an emergency arises, you should seek appropriate emergency medical services.

For UPMC Mercy Patients: As a Catholic hospital, UPMC Mercy abides by the Ethical and Religious Directives for Catholic Health Care Services, as determined by the United States Conference of Catholic Bishops. As such, UPMC Mercy neither endorses nor provides medical practices and/or procedures that contradict the moral teachings of the Roman Catholic Church.

© UPMC
Pittsburgh, PA, USA UPMC.com