Children whose mothers binge-drank while pregnant suffer from very specific attention and memory deficits not observed in youngsters whose mothers generally abstained while pregnant, according to new research findings that might lead to more targeted treatments and therapies.
The March of Dimes estimates that 40,000 American babies are born every year with neurological and developmental damage stemming from their mothers' alcohol consumption while expecting. These include Fetal Alcohol Syndrome (FAS) and other Fetal Alcohol Spectrum Disorders (FASDs).
Alcohol is toxic to developing brains and bodies. It crosses the placenta into the fetus' bloodstream, where it interferes with levels of oxygen and nutrients necessary for proper growth and development. Sufferers are more prone to aggression, infection and sleep disturbances, and suffer from higher rates of substance abuse and HIV infection.
"We've known for a long time that binge drinking, heavy drinking with pregnancy is associated with cognitive deficits," which affect short-term memory, arithmetic and information processing, said Joseph L. Jacobson, a developmental psychologist at Wayne State University School of Medicine in Detroit.
He said there's a wide range of effects, even when two pregnant women drink the same amount of alcohol: "One child may be more affected than another. It's a very complicated process."
Jacobson has spent years evaluating effects of prenatal alcohol exposure. In one long-term Detroit-based study, he and his colleagues found significant deficits in infants born to women who had as many as five alcoholic beverages at a sitting while pregnant. Other research has tied prenatal alcohol exposure to poor performance on batteries of neuropsychological tests.
But in a new study released Tuesday, Jacobson and colleagues at Wayne State and Laval University in Quebec City assessed subtle differences in youngsters' brains in another way. They used electroencephalograms to monitor changes in electrical activity in the brains of 217 Inuit children from Arctic Quebec while they underwent memory and coordination tests.
The children, whose average age was 11, included 38 boys and girls whose mothers reported binge-drinking during pregnancy, and 101 healthy youngsters who served as comparisons. (The majority of the healthy youngsters' moms were abstainers, although some drank moderately, Jacobson said).
The researchers measured so-called event-related potentials (ERPs), which are the brain's specific responses to thoughts or events. Scientists record brain wave changes taking place as the brain processes information and formulates responses. The technique has been used previously to study adults with chronic alcoholism and children at risk of becoming alcoholic.
Children in both groups performed comparably in measures of how long it took them to come up with an answer and how accurately they remembered an image they'd seen, called recognition memory.
However, those children exposed to heavy drinking before they were born were less able to understand the meaning of a stimulus, paid less attention to specific tasks and had poorer memory processing than the healthy controls, Jacobson and his co-authors reported. Their findings will appear in the January 2011 issue of the journal Alcoholism: Clinical and Experimental Research.