Mums-to-be who drink the equivalent of only two large glasses of wine once or more a month are putting their unborn baby’s health at risk, Bradford researchers revealed today.

It is the first time in the UK that doctors have been able to prove a clear link between women who consume excess alcohol during pregnancy and low-weight births.

Researchers at the Born In Bradford (BiB) project, who studied the drinking habits of 11,000 mums across the city, say “binge drinking” women who are between three-to-six months pregnant are increasing their risk of having a small baby by almost 70 per cent.

Professor John Wright, who is in charge of the research project, said binge-drinking for a pregnant woman is classed as drinking two large glasses of wine on one occasion one or more times a month and that will come as a big shock to many, sending out “a crisp message” to expectant women who want to give their babies the best start in life.

The project found that as many as one in ten babies are born in the city with a lower than expected birth-weight which can be linked to their mothers continually drinking more than the recommended daily alcohol allowance of one to two units once or twice a week.

Forty per cent of white British women taking part in the project admitted drinking alcohol while pregnant with 3.1 per cent of them confessing to binge drinking during their second trimester.

Prof Wright said: “Our message is very practical. Be cautious – don’t drink if you’re pregnant. You can only lecture people so much but we have got good evidence about drinking and harm to babies.”

However, researchers found no relationship between binge drinking and premature birth and no increase risk of low weight babies for women who drank low or moderate levels of alcohol during pregnancy.

Dr Duncan Cooper, who was the lead author of BiB’s new report, said: “This Born in Bradford research looks at the risk of binge drinking during the different periods of pregnancy.

“It demonstrates a 68 per cent increase in the risk of a small baby for women who binge drink during the second trimester and supports evidence of a dose-response relationship between alcohol consumption and the risk of foetal growth restriction.

“Growth-restricted babies have a greater risk of various neonatal complications including breathing problems, respiratory infections and hypothermia and impaired neurodevelopment.

“Our findings support Government policy that while there is no risk from drinking small amounts of alcohol during pregnancy, women should not binge drink as there are significant risks and consequences for their unborn child.”

The results from the research will now be used to put out public health messages and help women make informed decisions during pregnancy.

The BiB authors found that while a quarter of the mums binge drank before pregnancy, this fell to nine per cent during the first trimester and three per cent during the second.

Recent European studies estimate that between 30 to 70 per cent of women consume alcohol during pregnancy, while the numbers binge drinking can vary from three per cent to 26 per cent.

Prof Wright added: “There are various services locally in Bradford and across the country to help women cut down or stop drinking, or deal with alcohol dependency, but the best place for women to start discussing these issues is with their GP or midwife.”

Dr Shirley Brierley, consultant in public health for Bradford Council, welcomed the research findings and said: “Our advice for women across the Bradford district is to try to avoid drinking alcohol while pregnant or trying to conceive.

“If you drink a high volume during pregnancy, your baby is at risk of developing brain abnormalities and other health problems. You can drastically reduce these risks by avoiding alcohol during pregnancy or only drinking very small amounts.”