While distinct facial features are thought of as the marker of fetal alcohol syndrome, the effect of alcohol on fetuses may not show any outward signs.

According to information from the National Institutes of Health, many children may show signs of fetal alcohol syndrome solely cognitively or behaviorally. According to the NIH, about 44 percent of children whose mothers drank four or more drinks a day during pregnancy experienced some kind of abnormality. Forty-two percent of these alcohol-exposed children experienced language delays, 35 percent experienced cognitive delays, 27 percent experienced hyperactivity, 27 percent experienced delayed growth and 17 percent experienced abnormal facial features.

Researchers are trying to raise awareness about the other impairments, fearing that without the distinctive facial features, the children will not receive proper diagnosis or treatment.