Children born to women who drink one small glass of wine a week while pregnant are not likely to suffer any cognitive or behavioural problems, research suggests.
Light drinking during pregnancy "is not linked to adverse behavioural or cognitive outcomes in childhood", the new study found.
Previous studies have linked heavy drinking during pregnancy to health and development problems in children. But the authors wanted to examine the effects of low-level consumption.
The study, published in BJOG: An International Journal of Obstetrics and Gynaecology, saw more than 10,000 seven-year-olds take cognitive tests and their parents and teachers completed interviews and questionnaires to test the children's social and emotional behaviour.
The findings suggested that children born to light drinkers - those who drank two units or less a week - had lower behavioural difficulty scores than children born to mothers who abstained from drinking during pregnancy. Similarly they were found to have higher cognitive test scores for reading, maths and spatial skills tests.
However, when the authors adjusted the score for potential confounding factors, most of the results did not prove to be significant.
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But boys born to mothers who drank small amounts during pregnancy were found to have significantly better reading and spatial skills.
The paper concludes that while children born to light drinkers appeared to have more favourable developmental profiles compared to those born to mothers who did not drink during pregnancy, after statistical adjustment these differences largely disappeared.
"In this large, nationally representative study of seven-year-olds,there appeared to be no increased risk of a negative impact of light drinking in pregnancy on behavioural or cognitive development," the authors wrote.
"Prior to statistical adjustment, children born to light drinkers appeared to have more favourable developmental profiles than children whose mothers did not drink during their pregnancies, but, after statistical adjustment,the differences largely disappeared.
"Our findings... support the suggestion that low levels of alcohol consumption during pregnancy are not linked to behavioural or cognitive problems during early to mid-childhood."
Professor Yvonne Kelly, co-author of the study from University College London , said: "There appears to be no increased risk of negative impacts of light drinking in pregnancy on behavioural or cognitive development in seven-year-old children.
"We need to understand more about how children's environments influence their behavioural and intellectual development. While we have followed these children for the first seven years of their lives, further research is needed to detect whether any adverse effects of low levels of alcohol consumption in pregnancy emerge later in childhood."
The Government's advice to women who are pregnant or trying to conceive is that they should avoid alcohol altogether.
But if they choose to drink they should not consumer more than one or two units once or twice a week.