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Pathology => Human Diseases => Fetal Alcohol Syndrome (FAS)
Fetal Alcohol Syndrome (FAS)
INTRODUCTION
Fetal Alcohol Syndrome (FAS), mild to severe mental and physical damage to the fetus (the unborn child in the mother's uterus) caused by the mother's use of alcohol during pregnancy. FAS affects about 1 to 3 in every 1000 live births worldwide, and is the leading known cause of mental retardation in the Western world. French researchers at the University of Nantes in 1968 were the first to make a connection between maternal use of alcohol during pregnancy and birth defects in children. Five years later, American geneticists at the University of Washington in Seattle termed this condition fetal alcohol syndrome.
Children with FAS are small in size and weight at birth and have slow growth rates throughout their development. A child with FAS has characteristic facial features that may include short eye slits, a flattened midface, a smooth and elongated space between the nose and mouth, and a narrow upper lip. Children diagnosed with FAS show evidence of damage to the central nervous system that may be in the form of mental retardation, learning disabilities, developmental disabilities, seizures, or small head size. A child with FAS may develop visual and hearing problems, heart defects and other physical problems, and behavioral problems.
Researchers have found that some individuals who were exposed to alcohol during fetal development show only some of the characteristics of FAS. These individuals are described as having fetal alcohol effects (FAE). However, both FAS and FAE individuals may have some degree of brain damage.
HOW ALCOHOL AFFECTS THE FETUS
Researchers have proven that alcohol is toxic to the fetus, although exactly how alcohol causes damage is not fully understood. Alcohol can harm fetal cells. It also affects the placenta, the organ through which the fetus absorbs oxygen and nutrients from the mother, reducing the blood flow to the fetus and causing a severe shortage of oxygen.
The extent to which a fetus is damaged by exposure to alcohol depends on when the mother consumed alcohol during her pregnancy, and how much alcohol she consumed, among other factors. Studies of pregnant animals that were fed alcohol have led researchers to conclude that major physical defects in the human embryo, the early developing organism, can be caused by exposure to alcohol in the first trimester-that is, the first three months of pregnancy. Decreased fetal growth is associated with exposure to alcohol in the third trimester. Brain damage can result from exposure of the fetus to alcohol at any point during the pregnancy.
Researchers know that the more alcohol the mother drinks and the longer the fetus is exposed to the mother's alcohol consumption, the more severe will be the child's birth defects. Binge drinking, or heavy alcohol consumption at one sitting, is particularly hazardous to the fetus, because very high levels of alcohol enter the mother's blood stream, and the alcohol is passed into the blood of the fetus through the placenta.
The United States surgeon general recommends that women stop drinking alcohol entirely during pregnancy. Women who are trying to become pregnant, or who suspect they are pregnant, are urged to stop using alcohol in order not to damage the developing embryo.
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