Unlike heavy drinking, the evidence for a link between moderate to light consumption of alcohol and harm to the developing foetus is far from clear-cut, says Dr Gavaghan.Doctors' advice on the issue, including that of the Chief Medical Officer for England, is paternalistic and could be damaging in the long-term as the public loses faith in their expertise, he said.Dr Gavaghan said: "The British Medical Association expresses concern anything less than a recommendation of total abstinence risks being interpreted as a 'green light' for heavier drinking."But the opposite possibility must also be considered, that if they are seen to be exaggerating risks that recent and well publicised studies have shown to be negligible, their advice on genuine risks will carry less authority."It may, in short, be important for bodies like the Department of Health and BMA to consider whether they are in danger of 'crying wolf', with the attendant risk that genuine warnings of real dangers will be treated less seriously."In 2007 the government changed its stance and, despite the lack of new evidence, recommended total abstinence during pregnancy closely followed by similar advice from the British Medical Association.But a year later the National Institute for Health and Clinical Excellence (NICE) said that there was no evidence of harm provided women drank no more than one or two units a week.