A new study has found that heavy drinking during pregnancy could cause mental and behavioural problems in babies - by altering the genetic makeup of their brains in the womb.
Babies born to alcoholic mums have been found to be at risk of issues ranging from poor brain development, faulty nervous systems and loss of hearing and vision which stays with them throughout their lives.
Previously, scientists have not established how alcohol causes such irreversible damage to a baby's developing brain, but new research by neuroscientist Jerold Chun from the Scripps Research Institute in California has looked at how alcohol affects the brains of mice as they grow in their mum's womb.
The research team specifically looked at the number of chromosomes in the baby mice's brain cells before and after they were exposed to alcohol.
The mice were given the equivalent of two or three bottles of wine two weeks into their gestation.
The effects were evident very quickly - just one day later, the researchers found a threefold rise in neurons with more than five extra or missing chromosomes.
Mr Chun said of the findings: "This represents a new, unrecognised basis for altered neural function, which could contribute to developmental defects seen in animal models and human patients."
Did you avoid booze entirely during pregnancy?