BELLEVUE, WASH. – Many young adults who were exposed to alcohol prenatally have persistent difficulties with math, according to study findings reported at the annual meeting of the Teratology Society.
A team from Emory University in Atlanta performed long-term follow-up with repeated testing of a cohort of infants who were exposed to alcohol when their mothers drank during pregnancy. At the most recent assessment, they had a median age of 23 years; most were African American and of low socioeconomic status.
Dr. Claire D. Coles
The study results showed that the young adults who had physical or cognitive effects from their prenatal alcohol exposure had summary math scores that were 10%-11% lower than those in unexposed peers and 3%-4% lower than those in peers who had had childhood disabilities requiring special education.
Detailed testing showed that these affected young adults had difficulty with even simple math skills, such as counting dots and identifying which of two numbers is bigger.
Alcohol-related math dysfunction, including deficits in math achievement as well as in the simple elements that support math functioning, "which one would expect an adult would be quite competent at," persists into adulthood, commented first author Claire D. Coles, Ph.D., professor of psychiatry and behavioral sciences and pediatrics and director of the maternal substance abuse and child development project at Emory.
"Even when compared with other individuals with similar demographic characteristics who have developmental deficits, adults who are alcohol affected demonstrate specific math deficits," she added.
"I believe that alcohol may target neuropsychological functions, like working memory and full-scale IQ, that support math achievement. But I believe there are some other factors involved as well," Dr. Coles said.
Session attendee Dr. Kenneth L. Jones of the University of California, San Diego, asked, "Is this specific enough that you think it could be used as a screen in 5- or 6-year-old children?"
"I think that there is a specific math deficit in kids, yes, and it’s persistent," Dr. Coles replied. "Obviously, there is not a math part of our brain. But I think that whatever it is that alcohol does affects the functions that underlie the ability to do mathematics so that you are going to pick it up regularly in people who are affected."
Session attendee Rajesh C. Miranda, Ph.D., of the Texas A&M Health Science Center in Bryan, asked, "Is it possible to overtrain a person affected by fetal alcohol syndrome to overcome the deficits?"
"We have actually done an intervention program called MILE, which is the Math Interactive Learning Experience, in which we worked with the family and child specifically on remediating these issues. And it seems to be quite effective," Dr. Coles replied. "I’m not saying it magically fixes everything, but it does help with developing some of these underlying factors and improving outcomes."
In the study, the investigators split the alcohol-exposed young adults into three groups: 48 who had physical effects from exposure, 37 who had only cognitive effects from exposure, and 38 who were clinically unaffected by their exposure.
They were compared with each other and with two control groups: 59 unexposed adults matched for socioeconomic status and 54 adults who had had disabilities as children requiring special education.
Scores on a test for math achievement, the Woodcock-Johnson, 3rd edition (WJ-III), showed a significant difference (P less than .01) across the five groups with respect to the broad math (summary) score and with respect to scores for the individual subtests (math calculation, math reasoning, math fluency, applied problems, and quantitative concepts), reported Dr. Coles.
There was a general pattern whereby scores were lower in the young adults prenatally exposed to alcohol who had physical or cognitive effects, compared with all of the other groups.
In a regression model attempting to sort out the factors explaining math performance, significant contributors (P less than .01) included study group, dysmorphic features, working memory, and full-scale IQ.
In addition, scores on the EC301 test of math skills, a standardized test for brain-damaged adults, showed that the group with physical effects of alcohol exposure performed more poorly than all other groups with respect to counting and precise number knowledge. And the groups with physical and cognitive effects performed more poorly than all of the other groups with respect to number comparisons, mental calculations, estimating the results of arithmetic operations, and other measures.
Dr. Coles disclosed no relevant financial conflicts.