Women who are pregnant can safely drink a small glass of wine each day, according to draft guidance from the National Institute for Health and Clinical Excellence (NICE).
The organisation has produced guidelines which state that pregnant women can consume up to 1.5 units of alcohol a day after they have been pregnant for three months.
This advice contradicts that issued by the Department of Health (DH), which in May advised pregnant women and those trying to conceive to avoid alcohol altogether.
NICE said there is "no consistent evidence" to show a small amount of alcohol damages unborn children.
A NICE spokesman said: "The experts developing this guideline have carried out a systematic review of all the evidence available on the risks of drinking alcohol in pregnancy. The recommendations in the draft guideline are based on this evidence.
"The experts have concluded that there is no consistent evidence of adverse effects from low to moderate alcohol during pregnancy (less than one drink or 1.5 units per day) but the evidence is probably not strong enough to rule out any risk."
The risks of birth defects, miscarriage and behavioural problems among children of drinking mothers were considered.
The experts concluded women should avoid alcohol only during the first trimester, but said drinking led to a slightly higher risk of miscarriage.
However, the Royal College of Obstetricians and Gynaecologists said the "safest option" was for pregnant women to abstain from drinking.
NICE's guidelines are out for consultation and are due to be published in March.