Women with higher levels of income and education are more likely to drink alcohol weekly during their pregnancy, new figures have shown.
While more than one in 10 mothers (13 per cent) smoked all the way through their pregnancy, there was an increased risk of smoking linked to being poor and having lower levels of education.
The findings are from a new report, Maternal Health Behaviours and Child Growth in Infancy, published as part of the Growing Up in Ireland study.
The report draws on data from a cohort of 11,134 infants and their families.
Women with higher levels of education and income being more likely to drink alcohol in pregnancy was a "common finding internationally", said Prof Richard Layte of the Economic and Social Research Institute (ESRI) and co-author of the report .
“As to why, we don’t have exact data on this. Clearly those women feel that it’s an acceptable risk. The guidelines in Ireland are women should not drink in pregnancy.
“There is no strong evidence at the moment that low consumption of alcohol has a long-term impact on the child. That might be wrong, just the studies haven’t shown yet. We are reliant on observational studies,” he said.
“They tend to be more regular drinkers but quite less likely to binge-drink. A unit is about a glass of wine, not very strong wine, or half a pint of beer, of not very strong beer,” he said.
About 10 per cent of the women in the study drank alcohol and about 7 per cent of those drank under two units a week, he said, adding that 3 per cent of women in the study reported they drank more than two units of alcohol a week.
Prof Layte said there was a link between women who smoked and drank alcohol in pregnancy.
“Women who smoke are more likely to drink during pregnancy.
“It’s quite rare for someone who will smoke and not consume alcohol in some level. That’s not to say they drink to excess.”
The statistics showed women who experienced “a great deal of stress” were 37 per cent more likely to smoke. Prof Layte said the social circumstances were very important influencers on a pregnant woman’s health behaviours.
The study showed if a woman’s partner continued to smoke during the pregnancy, the mother was 70 per cent less likely to quit.
“Even if she stops smoking, the child’s birth weight will still be lower as a result of the passive smoking.”
Prof Layte said the figure of 13 per cent of women in Ireland continuing to smoke through their pregnancy was about average with Europe.
The study also found the proportion of women in Ireland who smoked at all in pregnancy dropped from 28 per cent in 1999 to 17 per cent in 2007.