There is scant evidence that occasional binge drinking during pregnancy can harm the unborn child, say scientists.
Drinking alcohol in pregnancy is not recommended
But they insist that pregnant women should follow advice to drink little or no alcohol.
The Oxford University study, published in the Journal of Epidemiology and Community Health, did not find links between bingeing and birth defects.
Official guidance says women should abstain from alcohol completely if pregnant or trying for a baby.
The relationship between sustained heavy drinking in pregnancy and health problems for mother and child is well-established.
In the most severe cases, it can cause miscarriage or stillbirth, or permanent damage to the growing foetus.
A small number of babies in the most severe cases can be born with "foetal alcohol syndrome", with symptoms including growth and mental retardation.
In recent years, however, the number of women who "binge drink" - defined as drinking five or more drinks at a single sitting - has grown rapidly, almost doubling in the 10 years from 1992.
The government has urged women to avoid binge-drinking completely during pregnancy, and the British Medical Association has gone a step further, suggesting that pregnant women should avoid alcohol altogether as a precaution.
The team from the National Perinatal Epidemiology Unit at Oxford University looked at hundreds of studies from across world into alcohol during pregnancy, and selected just a handful that allowed them to see the effects of binge drinking as opposed to sustained heavy alcohol use.
They found "no convincing evidence" that binge-drinking could harm the foetus, except for a two studies which hinted that a child could be born with very slightly lower IQ or show differences in behaviour.
The study authors said that fresh research into the issue was needed, and pointed out that the study could allow doctors to offer some reassurance to women worried about the effects of a single binge during their pregnancy.
However, Dr Ron Gray, the lead author, said that the research did not give women a licence to drink during pregnancy, saying that future research could uncover evidence of harm.
"I wouldn't want anybody to believe that, on the basis of this report, that it was safe to binge drink.
"We just don't know."
A spokesman for the BMA said that women should still think carefully about drinking any alcohol during pregnancy.
"Women want the best for their unborn child and while there is any doubt about the safety of consuming alcohol when pregnant, the BMA would advise women to abstain."
Patrick O'Brien, from the Royal College of Obstetricians and Gynaecologists, said: "I see a lot of pregnant women who tell me that in the weeks before they found out they were pregnant, they went binge drinking.
"It will be good to be able to tell them not to panic about it."
Mervi Jokinen, of the Royal College of Midwives (RCM), said: "The RCM is deeply concerned that this study could imply that there is little substantive evidence that binge drinking while pregnant seriously harms a developing foetus and gives the impression that drinking during pregnancy is safe."