Low levels of alcohol during pregnancy could also be risky for the baby

15/08/05 Decades of research have left little doubt that prenatal alcohol exposure has adverse effects on intellectual and neurobehavioral development. A recent study of the effects of moderate to heavy prenatal alcohol exposure on cognitive function confirms earlier findings of slower processing speed and efficiency, particularly when cognitive tasks involve working memory. Results are published in the August issue of Alcoholism: Clinical & Experimental Research.

"Prenatal alcohol exposure is often associated with slower reaction times and poorer attention in infancy, and some of these deficits may be at the core of poorer academic performance and behavior problems often seen later in childhood," said Matthew J. Burden, postdoctoral research fellow at Wayne State University School of Medicine and corresponding author for the study. "In cases of fetal alcohol syndrome (FAS) -- lower IQ scores are common, often reaching the level of mental retardation. This is because alcohol consumed by the mother has a direct impact on the brain of the fetus. However, full FAS is not required to see this impact; it is just less obvious to detect across the array of exposures found in fetal alcohol spectrum disorders (FASD), which include effects of prenatal alcohol at lower drinking levels."

Julie Croxford, graduate research assistant at Wayne State University, says there is a need for researchers to look at the damage caused by prenatal alcohol exposure at lower-than-heavy levels of drinking. "In the past, much focus was placed on studying the full-blown FAS," she said. "More recent research has considered those individuals damaged by lower levels of exposure. This is an important focus."

For this study, researchers assessed 337 African-American children (197 males, 140 females) at 7.5 years of age; selected from the Detroit Prenatal Alcohol Longitudinal Cohort, the children were known to have been prenatally exposed to moderate-to-heavy levels of alcohol. Their mothers were originally recruited between September 1986 and April 1989 during their first prenatal visit to a maternity hospital clinic. The children were assessed on processing speed and efficiency in four domains of cognitive function -- short-term memory scanning, mental rotation, number comparison, and arrow-discrimination processing -- using a Sternberg paradigm, which examines speed of completion as problems become increasingly more difficult.

Although the alcohol-exposed children were able to perform as well as the other children when tasks were simple -- such as naming colors within a timed period -- when pressed to respond quickly while having to think about the response, their processing speed slowed down significantly.

Alcoholism: Clinical & Experimental Research (ACER) is the official journal of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism. Co-authors of the ACER paper, "The Relation of Prenatal Alcohol Exposure to Cognitive Processing Speed and Efficiency in Childhood," were: Sandra W. Jacobson of the Department of Psychiatry and Behavioral Neurosciences at Wayne State University School of Medicine; and Joseph L. Jacobson of the Departments of Psychiatry and Behavioral Neurosciences, Obstetrics/Gynecology, and Psychology at Wayne State University. The study was funded by the National Institute on Alcohol Abuse and Alcoholism, the National Institutes of Health, and the State of Michigan.

http://www.sciencedaily.com/releases/2005/08/050814162218.htm