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An infant with anencephaly.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


A fetus lacking all or most of the brain.
[G. an, without, + enkephalos, brain]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


(an?en-sef'a-le) [Gr. an-, not, + enkephalos, the brain]
Congenital absence of the brain and cranial vault, with the cerebral hemispheres missing or reduced to small masses. This condition is incompatible with life. In the U.S., it is present in about 11 births out of 100,000. This defect results from the lack of closure of the anterior neural tube. Like other neural tube defects, the risk for anencephaly can be reduced with folic acid supplementation (800 mg daily) taken by women before and during pregnancy. See: neural tube defect
anencephalicanencephalus (an?en-se'fal-ik) (an?en-sef'a-lus), adjective
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
Regional differences in prenatal diagnosis and early termination of pregnancy may account for some of the differences in the rates for anencephalus, spina bifida, and encephalocele.
Findings of the subcategories of neural tube defects including anencephalus, spina bifida, and hydrocephalus were also mixed, and none of the studies found a statistically significant association except for Shaw et al.
Central nervous system defects (including anencephalus and similar anomalies, spina bifida, and other congenital anomalies of the central nervous system and eye) were the second largest group, occurring in 1991 (14.9%).
Six major CNS defects were reported: one case of spina bifida, two anencephalus cases, two hydrocephalus cases, and one case of multiple congenital anomalies.