Light drinking in pregnancy has no effect on premature birth, small babies or low birthweight, research has suggested.
Experts reviewing 36 studies on the issue found no link between low to moderate amounts of alcohol and three major risks to a baby.
However, the research did confirm previous studies which have shown that heavy drinking in pregnancy increases the chance of a baby being born premature, small for their gestational age or too light.
Government advice says pregnant women and those trying to conceive should avoid drinking alcohol. If women do choose to drink, they should drink no more than one or two units of alcohol once or twice a week and should avoid getting drunk.
Previous studies on the risks of light to moderate drinking in pregnancy have shown mixed results while this latest research found a "cut off" of 10g to 18g alcohol a day above which there were risks to the growing foetus.
The more women had to drink above this level, the higher the risks, but there were no apparent problems below 10g a day.
Heavy drinkers - those consuming 36g a day - were 23% more likely to have a premature birth than those who did not drink and were more likely to have a small baby.
In the UK, one unit is 8g of alcohol, equivalent to a pub measure of spirits, half a standard glass (175ml) of wine and half a pint of 3.5% beer, cider or lager.
Writing in BJOG: An International Journal of Obstetrics and Gynaecology, the researchers concluded: "Dose-response relationship indicates that heavy alcohol consumption during pregnancy increases the risks of all three outcomes whereas light to moderate alcohol consumption shows no effect."
They added: "This analysis adds weight to previous findings that light to moderate alcohol consumption during pregnancy does not increase the risks of low birthweight, preterm birth and small for gestational age."