A mother who inflicted lifelong damage on her child after drinking heavily during her pregnancy did not commit a criminal offence, the court of appeal has ruled.

Handing down the judgment, Lord Justice Treacy said the central reason for dismissing the appeal was that: “a mother who is pregnant and who drinks to excess despite knowledge of the potential harmful consequence to the child of doing so is not guilty of a criminal offence under the law if her child is subsequently born damaged as a result.”

The case, which was brought against the Criminal Injuries Compensation Authority by the local authority that cares for the child, sets a clear precedent for women’s rights.

The British Pregnancy Advisory Service had opposed the potential criminalisation of expectant mothers.

Treacy said the main reason for dismissing the application was that the damage caused to the unborn baby by heavy drinking was inflicted at an early stage of the pregnancy when the child did not have a separate existence under the law.

“The time at which harm, acknowledged in this case to amount to grievous bodily harm, occurred was whilst [the child] was in the womb,” he said in his judgment. “At that stage the the child did not have legal personality so as to constitute ‘any other person’.

In the judgment, the Master of Rolls, Lord Justice Dyson, said: “Parliament could have legislated to criminalise the excessive drinking of a pregnant woman but it has not done so … Since the relationship between a pregnant woman and her foetus is an area in which parliament has made a (limited) intervention, I consider that the court should be slow to interpret general criminal legislation as applying to it.”