Fri May 26, 2006
By Megan Rauscher
NEW YORK (Reuters Health) - For pregnant women, even a few alcoholic beverages per week during the first or second trimester can have harmful consequences on the cognitive development of the unborn child.
A long-term study has found that 10-year-old African-American children who were exposed to between two to six drinks per week during pregnancy, particularly in the second trimester, had a lower IQ compared with children who were not exposed to alcohol while in the womb.
"IQ is a measure of the child's potential to learn and survive in his or her environment. It predicts how successful we will be in school, work and life," study chief Dr. Jennifer A. Willford of the University of Pittsburgh School of Medicine noted in a university statement.
"The results of this study show that low-to-moderate levels of prenatal alcohol exposure has a sustained negative effect on child IQ," she added in comments to Reuters Health.
It's well known that heavy drinking during pregnancy can lead to lower intelligence in children, but less is known about the effects of light-to-moderate drinking during pregnancy on the child's IQ, Willford and colleagues note in the journal Alcoholism: Clinical and Experimental Research.
To investigate, the team examined data from 636 mother-child pairs who attended a prenatal clinic from 1983 to 1985. The women provided information on alcohol use during each trimester of pregnancy and their child's cognitive ability was assessed at age 10.
In African-American 10-year-olds, low-to-moderate alcohol exposure in the first and second trimesters significantly predicted deficits in the composite score of a standard test of intelligence, as well as several individual components of the test.
No such association was found for Caucasian children in the study. "This racial difference could not be explained by the amount or pattern of drinking during pregnancy or socioeconomic factors," Willford told Reuters Health. This suggests that genetics play a role in these racial differences, the investigators add.
Willford noted that "many women know about fetal alcohol syndrome and the potential dangers of prenatal alcohol exposure, particularly the damaging effects that heavy drinking can cause to a child's cognitive development. This study found that even light-to-moderate drinking during pregnancy can affect IQ."
The investigators also found that binge drinking "was not the best predictor of future cognitive defects in children whose mothers drank at light-to-moderate levels during pregnancy." Rather, the overall amount of alcohol consumed during pregnancy was more likely to predict whether or not a child's cognitive development would be impaired.
"Since no one has been able to determine if there is a 'safe' level of alcohol exposure during pregnancy, we can only say it's safer not to drink at all," Willford concludes.
SOURCE: Alcoholism: Clinical and Experimental Research, June 2006.