Light Drinking: Is There Really a ’Safe’ Level During Pregnancy?

Although a new study suggests pregnant women who drink lightly do no harm to their babies, this outcome may have nothing to do with alcohol.

Bloomberg News reported Oct. 5 that British researchers led by epidemiologist Yvonne Kelly, Ph.D., of University College London examined the social and emotional health of 11,500 five-year-olds born to women who either drank lightly during pregnancy (one or two drinks per week) or abstained. Data were collected from interviews with the mothers regarding alcohol use, education, family income, child-rearing habits, and the children’s development.

Contrary to what might be expected, children of women who drank lightly during pregnancy were one-third less likely to have behavioral problems and scored higher on cognitive tests than children of women who abstained.

However, these findings may not be related to alcohol at all, the authors point out.

For example, mothers in the study who drank lightly had twice the family income and education than their abstaining counterparts. Both factors affect parenting and environmental stress levels.

“There are many plausible explanations,” said Kelly in an interview.

Tim Naimi, MD, a physician at Boston Medical Center who specializes in alcohol research, couldn’t agree more.

“This study is hopelessly confounded by socioeconomic factors in that, as most people would be aware, people with high socioeconomic status generally have kids with much lower rates of behavioral and learning problems,” said Naimi in a Boston.com blog, White Coat Notes, on Oct. 7. “And yet these are the same women who may consume very small amounts of alcohol in pregnancy.”

“Alcohol is the leading fetal neurotoxin in the world. One would be challenged to come up with an explanation of why [the study results] would be biologically true,” Naimi concluded.

The study was published online Oct. 5 in the journal Epidemiology and Community Health.