Fetal Alcohol Syndrome
Reviewed by Marilyn T. Miller, MD, Professor
Fetal alcohol syndrome (FAS) is one of the most common, preventable causes of mental retardation in the world today. It may occur as often as Down’s syndrome and neural tube defects. FAS is estimated to occur in one to three cases per 1,000 individuals. At least one third to one half of children born to chronic alcoholic mothers show some signs of fetal alcohol syndrome. Although geographic and cultural differences affect the amount of alcohol a pregnant woman drinks, FAS occurs in all races and is more often a problem in developed countries.
Some common characteristics of FAS are:
Facial abnormalities like telecanthus, where there is an increased distance between the inner corners of the eyes, and a thin upper lip.
Mild to severe mental retardation resulting in learning difficulties.
Low birth weight and height that persists through early childhood.
Abnormalities of the heart and other organs.
How FAS affects the eyes
Eye doctors are interested in FAS because of the frequent involvement of the eyes, which may cause significant visual impairment in children. Visual acuity (the ability to see detail) is reduced in over 50 percent of children with FAS. Some problems such as a high refractive error (as large amount of near- or farsightedness) can be corrected with eyeglasses. Other problems that are caused by abnormal or incomplete development of the eye during pregnancy can result in a permanent reduction of vision. For example, the optic nerve may be small or abnormally developed, causing vision impairment. Less commonly, the cornea (the clear surface of the eye) and iris (the colored part of the eye) may show malformations that severely limit vision. Strabismus (an eye turn) is present in 25 to 50 percent of children with FAS. Some other possible problems include cataracts (clouding of the lens) and nystagmus (involuntary rapid movements of the eye).
Changes in the eyelids are common in FAS but may not hinder visual development. Signs of FAS are telecanthus and a droopy eyelid (ptosis), which occurs in about 20 to 25 percent of affected babies.
Who does FAS affect?
Diagnosing FAS at birth can be difficult for a variety of reasons. Not all children with FAS display all the symptoms of the syndrome. There are also no lab tests to indicate FAS. Unlike cocaine, where tests can show whether the drug was taken in the past, the physician has no test to perform that would reveal a mother’s drinking habits. Suspicions may be aroused if the mother was drunk at prenatal visits or when she delivered. The only way to diagnose FAS is to find the characteristic signs and symptoms and discover a history of drinking during pregnancy. Many women will not admit to excessive drinking while pregnant.
Drinking six average drinks per day puts a fetus at definite risk to develop FAS. The amount of alcohol consumption that can lead to FAS cannot be anticipated; however, regular alcohol consumption is believed to cause an increase in fetal abnormalities. Although an occasional drink has not been proven to have harmful effects on the fetus, most obstetricians advise no alcohol during pregnancy.
Some children may have malformations due to excessive alcohol consumed during pregnancy but they lack the characteristic appearance of FAS. Such groups of children suffer from fetal alcohol effects (FAE). For example, a child with FAS may be mentally retarded and have visual limitations but may not show any facial abnormalities. About 20 to 30 percent of all infants with alcohol-related problems are thought to show full FAS ; Only 20 to 30 percent have a few symptoms, and 40 percent show fetal alcohol effects.
How long has FAS been around?
Most of the research on FAS has occurred in the last few decades. However, the knowledge that drinking large amounts of alcohol may harm the fetus has been around for centuries. Aristotle said; “foolish, drunken…women must bring forth children like unto themselves, ‘morosos et lenguidos.’” Cultural taboos in ancient Carthage based on Greek and Roman mythology forbade a bridal couple to drink, in order to avoid producing defective children
It was not until 1973 that a clear description of FAS was made, and only recently have there been studies describing FAS in adolescents and adults. Although facial characteristics are not as distinctive with age, many problems remain. These individuals are shorter and have smaller heads, but their weight is closer to normal. Their IQ varies widely, but the mean is about 70 (normal IQ is about 100). FAS adolescents and adults continue to show behavioral problems such as being easily distracted, and having poor social interaction, making independent living difficult.
How can FAS be treated?
All children with evidence of alcohol effects during pregnancy should have a complete eye examination. Some of the visual problems can be improved with eyeglasses. More serious problems need to be identified early for treatment and ultimately to ensure proper school placement.
Fetal alcohol syndrome is a permanent, preventable problem. Women must realize that a few alcoholic drinks may not affect them, but it can severely hurt their unborn child.