London: There is "surprisingly limited" evidence that light drinking during pregnancy poses any risk to the baby, say UK researchers, reports BBC.

They reviewed all the available studies done on the topic since the 1950s and found no convincing proof that a drink or two a week is harmful.

The Bristol University team stress this does not mean it is completely safe.

They say women should avoid all alcohol throughout pregnancy "just in case", as per official guidelines.

But women who have had small amounts to drink in pregnancy should be reassured that they are unlikely to have harmed their baby.

The Chief Medical Officer for the UK, Prof Dame Sally Davies, updated her advice last year to advocate total abstinence.

Before that, pregnant women had been told they could drink one or two units - equivalent to one or two small glasses of wine - a week.

There is no proven safe amount that women can drink during pregnancy, although the risks of drinking heavily in pregnancy are well known.

Getting drunk or binge drinking during pregnancy increases the risk of miscarriage and premature birth and can lead to mental and physical problems in the baby, called foetal alcohol syndrome.

The risks associated with light drinking, however, are less clear.  Dr Luisa Zuccolo and colleagues found 26 relevant studies on the topic.