Alcohol During Pregnancy - Whats the Question?

Drinking alcohol in small amounts shows no cognitive effects in five European studies

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) To drink or not to drink? Such is the question for many expectant moms who would love to have that single glass of wine but worry about its impact on their developing baby.

While that decision will remain a personal one between the mother, her partner and her prenatal caregiver, a recent study provides some helpful information to figure into the decision.

A series of five studies looking at alcohol intake during pregnancy has found that low and moderate drinking each week is not linked to any neurological or psychological consequences in children when they are five years old.

The five-year-olds of women who drank larger amounts of alcohol, however, did have shorter attention spans than children of moms who abstained more.

"Avoiding alcohol while pregnant is still the safest policy."

Ulrik Schiøler Kesmodel, a gynecologist and associate professor at Aarhus University and Aarhus University Hospital, and Erik Lykke Mortensen, a professor of medical psychology at the University of Copenhagen's Institute of Public Health in the Medical Psychology Unit, led or co-authored the five studies.

The studies used data from 1,628 women, with an average age of 30, enrolled in the Danish National Birth Cohort and focused on the impact of mothers' low, moderate, high and binge drinking on their children at age 5.

A low level of drinking was considered one to four drinks each week, and moderate included five to eight drinks a week, or approximately one drink a day.

A drink was defined as 12 grams of pure alcohol. This definition of a "standard drink" is not necessarily the same in different countries, so 12 grams should be converted into the units used locally.

In the US, a standard drink is defined as 14 grams of pure alcohol by the National Institutes of Health. Therefore, an American standard drink is slightly more than the standard drink used by the Danish researchers in these studies. An equivalent US drink to the one used in the study is approximately 4.2 ounces of wine or 10.2 ounces of beer.

Those drinking "high" amounts of alcohol had nine or more drinks each week, and binge drinking meant having five or more drinks during a single time episode.

The authors considered the children's IQ, attention span and executive function, which is the broader, theoretical name for a collection of cognitive activities, including memory, organization, planning, problem-solving, verbal reasoning, mental flexibility, multi-tasking and self-control.

They used an assessment called Test of Everyday Attention for Children at Five to measure selective attention and sustained attention, and the children and mothers were given 3-hour IQ assessments at health clinics or university sites. The children's IQ testing involved five verbal tests and five non-verbal cognitive tests.

For the children of mothers who fell into the categories of low or moderate drinkers, the researchers did not find any differences in their children's test performance compared to the children of mothers who did not drink at all.

Moms who had more than nine drinks a week, however, had children with reduced attention compared to the abstaining mothers.

"Our findings show that low to moderate drinking is not associated with adverse effects on the children aged five," Kesmodel and Mortensen wrote. "However, despite these findings, additional large scale studies should be undertaken to further investigate the possible effects."

They caution that the safest policy continues to be abstinence from alcohol during pregnancy even though small amounts do not appear linked to cognitive problems for children.

John Thorp, the deputy editor in chief of the journal that published the studies, agrees that the safest route is to avoid alcohol while pregnant.

"More research is needed to look at long term effects of alcohol consumption on children," Thorp wrote in an editorial. "The best advice is to choose not to drink; however, small amounts have not been shown to be harmful."

The five studies appeared June 19 in BJOG: An International Journal of Obstetrics and Gynecology. The research was primarily funded by the U.S. Centers for Disease Control and Prevention. No information was available regarding authors' disclosures or conflicts of interest.

Reviewed by: 
Review Date: 
June 18, 2012
Last Updated:
October 30, 2012