Women in Ireland are among the most likely in the world to unintentionally harm their unborn baby by drinking alcohol during pregnancy, the HSE will warn today.

Ireland is estimated to have the third highest rate of Foetal Alcohol Spectrum Disorders (FASD), including Foetal Alcohol Syndrome, in a global study of 187 countries.

The condition can cause learning difficulties, organ damage and facial deformity, leaving children with a lifelong disability.

A HSE campaign today calls for zero tolerance for drinking during pregnancy and warns expectant mothers to avoid alcohol entirely while their baby is in the womb.

Dr Mary T O'Mahony, a HSE specialist in public health medicine, said: "Pregnant women receive conflicting advice about drinking during pregnancy, and are often assured by family and friends that an occasional drink won't do any harm.

"But the fact is that there is no proven level of safe drinking during pregnancy. FASD causes life-long problems for babies.

"We do know that heavy or frequent drinking is more dangerous, and the more you drink, the greater the risk to your baby. But the only way to have zero risk, is to drink zero alcohol."

A global league table showing Ireland is third highest for foetal alcohol related problems emerged two years ago in the journal 'JAMA Paediatrics'.

A recent survey found one in two people in Ireland were aware of illnesses and conditions that affect babies after birth as a result of exposure to alcohol during pregnancy. But only one in 10 had a good understanding of FASD, its symptoms and its cause.

The HSE said it had since spoken to women who are pregnant and women considering becoming pregnant.

"The overriding message we heard from these women was that there is a lot of misleading information and confusion around alcohol and pregnancy.

"There are so many opinions, voices, feelings and sources of advice that lead to confusion. There is a lack of clarity among this sea of voices and it can be very confusing to know the 'right thing' to do," it said.

Alcohol passes from the mother's blood into the baby's blood via the placenta and can damage the baby's developing brain and body.

FASD cause life-long problems for the baby's body, brain and development.

The problems include hyperactivity and poor attention, learning difficulties and a lower IQ, difficulty controlling behaviour and being smaller than expected.

The campaign points out that drinking in the first three months of pregnancy is particularly harmful as the unborn baby's body, organs and facial features develop.

Irish Independent