From 26 studies, the team found that drinking up to four units a week while pregnant, on average, was associated with an 8 per cent higher risk of having a small baby compared with drinking no alcohol.
But they said while there was an association, this did not prove a direct cause of smaller babies at birth.
The researchers said that overall there was insufficient data to "make robust conclusions", adding that evidence on the effects of light drinking was "sparse".
Australian expert Elizabeth Elliot, Professor of Paediatrics and Child Health at the University of Sydney and co-director of the NHMRC Centre of Excellence in Fetal Alcohol Spectrum Disorder, disagrees with the conclusion.
Elliot says there is a paucity of evidence of harm in offspring exposed to low levels of alcohol, but just because we can't see damage doesn't mean there is no damage.
"Even though there may be not obvious risk from low levels of alcohol our advice as health professionals must be the safest option is to avoid alcohol," Elliot said.
"We know that alcohol can cause harm both at a cellular level and a clinical level therefore the precautionary approach is safest and one of the reasons is that often people who are given the go-ahead to drink will drink more than they are advised to drink."
Dr Bernadette White at Mercy Health from the Royal Australian and New Zealand College of Obstetricians and Gynaecologists says she always advises against light drinking during pregnancy but when it comes to an occasional drink on a special occasion, common sense must prevail.
"Certainly I would say to women have one on a special occasion but don't drink on a regular weekly basis," said White.
- AAP
