No alcohol for mothers-to-be.
Although Department of Health guidelines advise that one or two units a week is safe, a study by a team at St George's Hospital Medical School in London suggested otherwise.
The findings, published in the British Medical Journal today, showed that foetal alcohol syndrome can lead to stunted growth, facial abnormalities and brain disorders.
The syndrome can also cause behavioural disorders such as hyperactivity and overlaps with conditions including autism and attention deficit hyperactivity disorder (ADHD).
Until now, these effects were thought to have been caused by heavy drinking during pregnancy.
But researcher Dr Raj a Mukherjee says one drink a week could be harmful.