They were attending a conference at UW-Madison, and the Friday morning topic was chemically induced birth defects in humans. Researchers are trying to unravel the molecular mechanisms by which substances such as alcohol disrupt human development. Showing slides of affected children, Jones noted that media reports often decry effects of illegal drugs such as marijuana, cocaine and heroin. Despite the evidence, the number of expectant mothers who admitted drinking alcohol increased from 12.4 percent in 1991 to 16.3 percent in 1995. No one is sure how many children are affected because there is no mechanism to keep count and because many children are never properly diagnosed.
Estimates vary wildly.
The Center for Disease Control uses the most conservative estimates, which put the range of FAS babies at somewhere between 800 and 4,000 a year . Scientists suspect the devastation comes from alcohol's effects on the baby's brain as it forms facial structures and controls movement in the womb. But scientists don't know why some women drink a lot and have apparently normal babies, while others drink less but damage their infants. Some risk factors are known, but genetic factors may be critical. Metabolism may play a role.