Children born to mothers who drank light amounts of alcohol while pregnant show no signs of behavioral or intellectual impairment in the first five years of life, according to a new study published in the Journal of Epidemiology & Community Health. In fact, when compared to children whose mothers didn’t drink while pregnant, the children of light drinkers appear more developmentally advanced.
Scientists from the University College London and Oxford University employed data from the Millennium Cohort Study—a large study tracking the long-term health of children born in the U.K. Their results will be used as the government crafts a National Alcohol Strategy, an initiative to curb a dramatic rise in binge drinking in Britain. One portion of the strategy will provide the National Health Service with tactics for helping pregnant women refrain from consuming too much alcohol. But to do so effectively, researchers had to determine responsible levels of consumption.
The team looked at Millennium Cohort Study data concerning 11,513 children born between September 2000 and January 2002 and their mothers. During the study, oral questionnaires were conducted and the mothers were asked about their alcohol consumption during pregnancy. The scientists classified mothers-to-be as teetotalers, light drinkers (1 to 2 units a week), moderate (3 to 6 units a week) and binge/heavy (7 or more units a week). One unit of alcohol was classified as half a pint of beer, a glass of wine or a single measure of spirit or liquor. (The study's definition of light and moderate drinking is based on notably lower amounts per week than are often used to define these categories; the USDA definition of moderate drinking for women is one glass a day.)
Once the children reached three years old, the mothers were quizzed about their children's behavior. The scientists then administered an intellectual assessment at age five. (The team published their early findings, based on the three-year assessment, in 2008. But the new report includes their testing of the children.)
In the study, 94 percent of the mothers admitted drinking regularly when not pregnant. Most did not drink while pregnant, but roughly 5,000 did. Of the total number of women, one in four reported light drinking, 5.5 percent were moderate drinkers and 2.5 percent were heavy or binge drinkers.
The children's cognitive abilities were measured by a vocabulary test, the ability to pick out visually similar objects and how well they could match patterns. Some qualitative measure were also used, such as how close the mother felt to her child and whether or not she could make the child follow her orders. The light-drinking women were slightly less successful in these categories when compared to never drinkers.
But overall, the scientists found that children born to light drinkers were 30 percent less likely to have behavioral problems than children whose mothers did not drink during pregnancy. "The bottom line is children born to light drinkers were not at increased risk of developmental difficulties compared with children whose mothers did not drink during pregnancy," said lead author Yvonne Kelly, of the Department of Epidemiology and Public Health, University College London.
On the other hand, children born to mothers in the heavy/binge drinking category were more likely to suffer from hyperactivity, conduct and emotional problems compared with children born to mothers who did not drink during pregnancy, the study concluded.
The scientists don't believe alcohol helps childhood development. Other factors may be at work. For example, light drinkers were the highest educated in the survey and held the best jobs. Instead, the team argues that responsible drinking while pregnant does not put the child at a long-term risk.
But Kelly adds that the motivation to drink or not to drink is too complex to give advice based on this study alone. "We are not in a position to advocate what women should or should not do during their pregnancies," she said. "But we think that women are able to make informed decisions in the context of their own personal circumstances."
Some of the study findings were fairly predictable—the girls were nicer to their peers, while the boys showed a greater tendency to misbehave.