Another good reason to quit drinking while you're pregnant - alcohol intake can increase your risk of premature birth.
Researchers at the Univeristy of Western Australia found that 10% of mums-to-be who binged or drank heavily gave birth prematurely, compared with 6% of mums who drank lightly or not at all when pregnant.
General advice is to avoid alcohol completely for the first 12 weeks of pregnancy, then limit your intake to no more than one or two units, once or twice a week.
Andrew Shennan, professor of obstetrics for Tommy's the baby charity, says pregnant women should try not to get too stressed if they drank in the early days, though.
'A huge number of women drink before they know they're pregnant and the vast majority have a safe pregnancy,' he says.
'Smoking heavily, being underweight or overweight are all risk factors for early birth, too. If you're getting any unusual symptoms, discharge, pain or bleeding, call your doctor immediately.'