Experts at the University of California, San Diego School of Medicine disagree with a series of new studies from Denmark that suggest consumption of up to 8 alcoholic drinks a week or occasional binge drinking during pregnancy is generally safe for the developing baby.

Kenneth Lyons Jones, MD, professor in the UCSD Department of Pediatrics and a renowned expert in birth defects, and Christina Chambers, MPH, PhD, director of the California Teratogen Information Service (CTIS) Pregnancy Health Information Line, say these studies are misleading to pregnant women, citing more than 30 years of research to the contrary.

"This series of studies collected data on alcohol exposure during an interview conducted sometime between 7 and 39 weeks of pregnancy. The quantity and frequency of alcohol consumed was based on mother's recall which may not be accurate," said Jones who was one of the first doctors to identify Fetal Alcohol Syndrome (FAS) in 1973.

Published in BJOG: An International Journal of Obstetrics and Gynecology, the series of studies analyzed data from more than 1,600 women in the Danish National Birth Cohort. The amount of alcohol consumed by the women during their pregnancy was classified as either none, low, moderate, or high. In addition, binge drinking was defined as having 5 or more drinks on a single occasion. When the child reached the age of 5, the children underwent various development tests. Researchers found no significant association between prenatal alcohol consumption at low and moderate levels and general intelligence, attention, executive function or IQ. However, only half of the women invited in the follow-up studies agreed to participate. It is possible that those women who drank during pregnancy and who agreed to participate were more likely to have higher functioning children.

Chambers, a UCSD School of Medicine professor, pointed out the overwhelming evidence of more than 30 years of research supporting the conclusion that alcohol, especially alcohol consumed in a binge pattern, can be harmful to the developing baby.

"Individual women metabolize alcohol differently, and vary in terms of how susceptible they may be to having an affected child," Chambers said. "Although we do not want to alarm women who find out they are pregnant and realize that they have consumed low levels of alcohol before they knew they were pregnant, we emphasize that a 'safe' amount of alcohol that any individual woman can drink while pregnant is impossible to establish. The best advice continues to be that women should avoid alcohol entirely during the nine months that she is carrying the baby."