To drink (a little) or not to drink? That's the question that fuels an ongoing debate over whether women should cut out all alcohol during pregnancy, or only consume alcoholic beverages in moderation.
While numerous studies -- some more accurate than others -- have amassed evidence for both sides, a U.K. study published this week indicates that a mother's light drinking during pregnancy is not linked to mid-childhood developmental problems in her kids.
Monitoring about 10,500 children from pre-birth through age 7, researchers determined that the children of mothers who drank up to two drinks per week fared just as well on a series of cognitive tests as kids born to mothers who did not drink while pregnant.
"Children born to light drinkers don't appear to be at any increased risk for developmental problems," Yvonne Kelly, a professor at University College London and co-author of the study, told The Huffington Post.
Despite these findings, she does not advise pregnant women to drink -- lightly or otherwise -- during pregnancy.
"From a neutral scientific perspective, we're not advocating that women should or shouldn't do anything particular," she said.
In the U.K., Kelly notes, occasional drinking during pregnancy is fairly common. Past studies have examined negative effects of heavy drinking during pregnancy, such as severe cognitive and behavioral problems; but before this project was launched, less was known about whether lower levels of alcohol consumption could lead to the same detrimental effects.
Funded by the Economic and Social Research Council, Kelly and her team evaluated data obtained from subjects at ages 3, 5 and 7, and compared markers of social and emotional development. The researchers also took other behaviors, such as the presence of hyperactivity and social disorders, into account. Comparing the groups of children, the team applied a statistical analysis to remove any potential effects of socio-economic conditions, since some families included in the sample were more affluent than others.
Though Kelly says she did not expect to see the same negative effects observed in cases of heavy drinkers, she said the team was still a bit surprised by the results.
"We thought we would see a hint of negative impacts," Kelly told HuffPost. But that was not the case. Instead, they found that light drinking during pregnancy did not lead to any discernible developmental effects by mid-childhood.
The findings, published in BJOG: An International Journal of Obstetrics and Gynecology, are reinforced by similar research conducted in recent years. In 2012, a group of studies out of Denmark indicated that children of mothers who drank up to eight alcoholic beverages per week while pregnant did not have a higher risk of problems relating to attention span or executive functions by age 5.
While other studies have produced contradictory results by examining the effects of light drinking during pregnancy on children's IQs, Kelly points out that she has seen certain pervasive issues with some other research, questioning the use of IQ as a valid form of measurement as well as small sample sizes.
"In any small-scale study, investigators often run into statistical problems because you can't be sure of what it is you're detecting," Kelly said, adding that in their study, her team had a high sample number and tried to control potentially confounding factors.
Kelly plans to follow up and review evaluations conducted on subjects at age 11. She does not expect to see any differences in the results.
The CDC recommends that women avoid alcohol for the entire time they are pregnant, advising: "There is no known safe amount of alcohol to drink while pregnant. There is also no safe time during pregnancy to drink and no safe kind of alcohol."