Women who drink even moderate amounts of alcohol while pregnant may risk lowering child’s intelligence levels, according to a study by British scientists.

Advice to pregnant women about drinking is contradictory, with some guidelines recommending no alcohol at all and others suggesting the odd drink now and then is safe.

But in a study described as “hugely important” by one expert, researchers using genetic analysis of more than 4,000 mothers and children found that drinking between one and six units of alcohol a week during pregnancy can lead to lower Intelligence Quotient (IQ) scores by the time a child is eight.

“Even at levels of alcohol consumption which are normally considered to be harmless, we can detect differences in childhood IQ which are dependent on the ability of the fetus to clear this alcohol,” said Sarah Lewis of Bristol University, who led the study. “This is evidence that even at these moderate levels, alcohol is influencing fetal brain development.”

This study used genetic data from women and children who were part of another study called the Children of the 90s study.

Since the individual genetic variations that people have in their DNA are not connected to lifestyle and social factors, this kind of study avoids potential complication