Birth defects too often blamed on alcohol.

Physicians and geneticists too readily blame birth defects on a mother's use of alcohol during pregnancy and may miss other genetic causes of the abnormalities, says an Arizona researcher. In a study of children previously identified as suffering from the effects of fetal exposure to alcohol, he found that 13 percent suffered from misdiagnosed genetic problems.

"Some of these children were labeled as suffering from mild cases of fetal alcohol effects, when in fact they have something entirely different," says H. Eugene Hoyme of the University of Arizona Health Sciences Center in Tucson. He urges doctors and geneticists to eliminate the diagnosis of fetal alcohol effects (FAE), considered a mild form of fetal alcohol syndrome.

First described in 1973, fetal alcohol syndrome, one of the most common causes of birth defects, occurs in 1 in 500 to 1 in 1,000 births. Children with the syndrome typically have smaller heads, small eye openings, flattened noses, and smooth upper lips. They also tend to be short and to have low IQs.

Diagnosis of the disorder hinges on facial abnormalities, short stature, and low IQ, says Hoyme. But children who don't meet all three criteria are often diagnosed with FAE, on the assumption that their birth defects arose from their mothers' drinking during pregnancy.

Some scientists, however, consider FAE such a catchall diagnosis that it obscures some important genetic diseases. Hoyme and his colleagues studied 437 Arizona children, 19 percent of whom had been diagnosed with fetal alcohol syndrome. The rest had diagnoses ranging from FAE to probably FAE to some FAE.

The team reanalyzed the cases, this time limiting the definition of fetal alcohol syndrome to the characteristic facial abnormalities. With this revision, the researchers diagnosed fetal alcohol syndrome in a whopping 56 percent of the children.

But they also found that 13 percent suffered from conditions such as Down's syndrome and neurofibromatosis-conditions doctors had previously failed to diagnose. The researchers classified 41 percent of the children as having had some prenatal alcohol exposure, but they could not link the birth defects to alcohol. Some of the children had two diagnoses.

"Any abnormality is now described as an effect of alcohol if the mother drank at all during pregnancy," says Hoyme. Even though drinking during pregnancy is a problem, "we risk stigmatizing children and missing other diagnoses which require medical follow- up if we too easily point to alcohol."