Mothers could be permanently damaging their babies by having even an occasional alcoholic drink during pregnancy, researchers warned.

It is well known that drinking heavily while pregnant can cause learning disabilities and physical abnormalities in the child. However, scientists in the U.S. have found that lower levels of alcohol can also have an effect on the child, by slowing down his or her memory.

The latest research follows a study, reported in the British Medical Journal, which found that small amounts of alcohol could harm unborn babies. The finding led to calls for the government in Scotland to change its guidelines, which say women can safely drink up to two units of alcohol a week.

The most-recent report is likely to lead to further calls to advise total abstinence from drinking during pregnancy, although childbirth charities say women should be given information rather than being lectured.

Wayne State University in Detroit studied 337 seven-year-old African-American children who were exposed to moderate to heavy levels of alcohol in the womb.

The research team found those children exposed to alcohol could perform memory, number and other tasks as well as other youngsters, as long as the tasks were simple, such as naming colors within a time period.

However, when the children were pressed to respond quickly while having to think about their response, their processing speed slowed.

Julia Croxford, one of the authors of the study, said it confirmed that moderate to heavy prenatal alcohol exposure affected youngsters' cognitive function.

"The real-world implications of this are that children exposed prenatally to alcohol may be able to perform simple tasks but may struggle with tasks that are more challenging and require complex cognition and the use of working memory," she said.

"This is likely to mean that these children may be more and more challenged the older they get by the demands placed on them within the school system and within their day-to-day social interactions."

She said that, even taking other lifestyle influences into account, alcohol caused specific, identifiable and permanent deficit in children's brain development. "This reinforces the current public health message that women should not drink alcohol during pregnancy," she said.

In the U.S., women are advised not to drink at all during pregnancy, but in Scotland, the advice is that one or two units a week is unlikely to harm the baby.

Campaigners in Britain already have said that the only 100% safe level of alcohol consumption during pregnancy is none.

However, Belinda Phipps, the chief executive of the National Childbirth Trust, said the most important thing was to give women the correct information rather than new orders.

"It is important that women expecting a baby are treated as adults and that research on alcohol in pregnancy is presented to them as easy-to-understand information, so they can make up their own minds what they will do about these risk factors," she said.

Source: The Scotsman