Effect of Light Drinking during Pregnancy

Pregnant women who drank 1-2 alcoholic beverages a week were unlikely to have harmed their babies, according to a new study. In fact, it may have been beneficial.

Yvonne Kelly, PhD, from the Department of Epidemiology and Public Health, University College London, United Kingdom, and colleagues examined data from a Millennium Cohort Study that followed over 11,000 children in the U.K. born between 2000 and 2002. Mothers were categorized according to drinking habits — a teetotalar drank alcohol but not while pregnant, a light drinker consumer 1-2 drinks per week, a moderate drinker 3-6 per week, and a heavy drinker 7 or more per week. 66% of the mothers in the study group fit either the teetotaler profile or did not drink at all, 26% were light drinkers, 6% moderate, and 2% heavy.

Mothers responded to questionnaires about their childs' behavior at age 3. At age 5 the children were evaluated using the Strengths and Difficulties Questionnaire and British Ability Scales.

The tests revealed that children whose mothers fell in the light-drinking category were about one third less likely to exhibit behavioral problems then those whose mothers did not drink while pregnant.

In addition, tests showed no intelligence difference between the children of light-drinking mothers and the rest of the group. In fact, children born to light-drinking mothers actually performed better in cognitive tests than children in the non-drinking mother category.

This study, Dr. Kelly told Medscape Medical News, suggests that, light drinking by mothers appears to result in "no increased risk of behavioral or intellectual problems in their children [at age 5]."

A Cautionary Note

Dr. Kelly and colleagues noted, however, that the testing was observational in nature and cautioned that "causal inference based on observational data is limited." They also noted that mothers' drinking patterns during pregnancy were determined by questioning them after their children were 9 months old, and that their reported recollection may be prone to recall bias.

Marc C. Lewis, MD, service chief for Women's Health Services at Henry Ford Hospital in Detroit, Michigan, said the study is "interesting, but certainly warrants much more long-term data."

Although the short-term data indicated no problems in children born to light-drinking mothers, "I agree with the authors' statement that further work to tease out etiological relationships is needed," Dr. Lewis told Medscape Medical News. "We know that in the United States, the leading cause of mental retardation is related to fetal alcohol syndrome," he added, "and although the study was for light drinkers, I do not believe we want to establish a precedent that any level of alcohol consumption is okay, because in truth, we really don't know the long-term effects of even light drinking."

Reference

J Epidemiol Community Health. Published online October 5, 2010. Abstract