PREGNANT women who drink just one small glass of wine a week can lower their unborn child’s future intelligence, a new study has warned.
Researchers have only now discovered that some children are genetically disposed to having their IQ lowered in the future if their mothers drank during pregnancy.
Even a small amount of alcohol before birth could have a significant impact on a child’s intelligence by the time they reach the age of eight, scientists found.
Previous studies provided conflicting and inconsistent evidence on the effects that low to moderate drinking during pregnancy can have on a baby. One of the reasons for the discrepancy has been that other social and lifestyle factors – such as smoking, diet and wealth – could affect the results of studies.
Experts have warned women of the dangers of heavy drinking while pregnant for the past two decades. They have outlined how the alcohol can affect a baby’s short and long-term health.
Some guidelines recommend mothers-to-be to avoid alcohol completely, while others suggest a moderate intake is safe and poses no risk to their child.
The latest study from the universities of Bristol and Oxford is believed to be the first to look at the effects of small levels of alcohol consumption. The study is the first to show genes have a strong bearing on the effect of alcohol in the womb.
Lead researcher Dr Ron Gray said: “This is a complex study, but the message is simple. Even moderate amounts of alcohol during pregnancy can have an effect on future child intelligence. So women have a good reason to choose to avoid alcohol when pregnant.”
More than 4,000 women and their children were assessed as part of the study. Researchers looked at four genetic variants in the youngsters – all of which are known to influence the body’s ability to metabolise, or break down, alcohol.
The teams looked at this in connection with the drinking habits of each child’s mother throughout her pregnancy, notably at 18 and 32 weeks.
The findings revealed mothers who drank between one and six units of alcohol per week – anything from a small glass of wine or a single measure of a spirit to two large glasses of wine – were likely to have a child with a lower IQ if they were genetically susceptible to the harmful effects of alcohol while in the womb.
At eight years old, IQ was reduced by almost two points for a gentically disposed child whose mother drank while pregnant.
Children whose mothers did not drink at all while pregnant were not affected, even if they had alcohol-sensitising genes, the study in the journal Public Library of Science ONE found.
Dr Sarah Lewis, of Bristol University, said the research revealed levels of alcohol that are normally considered “harmless” can have a negative impact on childhood IQ.
She said: “This is evidence that even at these moderate levels, alcohol is influencing foetal brain development.”
She described how alcohol passes easily from a mother’s bloodstream to her baby via the placenta. When alcohol enters the body, certain enzymes convert it to the chemical compound called acetaldehyde.