Children born to women who have as little as one drink a week during pregnancy are more likely to have symptoms of behaviour problems as teens, according to research published this month in the journal Paediatrics.

“If women stop drinking during pregnancy, they can save themselves a lot of heartache later. Being the parent of a child with conduct disorder is really frustrating,” Dr Elizabeth R. Disney of Chase Braxton Health Services in Baltimore, one of the researchers on the study, told said.

The ill effects of heavy drinking during pregnancy, specifically the cluster of social and cognitive problems known as foetal alcohol syndrome, are well known, Dr Disney and her team note in their report. There is also evidence that even a low level of prenatal alcohol exposure is associated with aggressiveness, delinquency and other so-called “externalising behaviours”. But women who drink during pregnancy are themselves more likely to have these and other problems – and may tend to choose mates that have such problems as well, the researchers point out.

To better understand the independent role of alcohol exposure in pregnancy, Dr Disney and her colleagues looked at 1,252 17-year-olds enrolled in the Minnesota Twins Family Study and their parents.

Among boys, about 36 per cent had symptoms that would qualify them for a “definite or probable diagnosis” of conduct disorder, according to the researchers, while about 10 per cent of girls did. Such symptoms include shoplifting, being aggressive to animals and people, setting fires, and skipping school.

Overall, about 31 per cent of teens born to mothers who admitted to having at least a drink a week while pregnant had conduct disorders, compared to 21 per cent of kids whose mothers didn’t drink at all.

The mums who drank alcohol while pregnant – 13 per cent of the total, who averaged about three drinks a week – were also more likely to smoke. Both parents in these families were more likely to have externalising behaviours. But when the researchers accounted for these and other possible “confounding” factors they found that prenatal alcohol exposure was independently linked to a significantly greater number of behaviour problems.

Among mothers who had been diagnosed with alcoholism, 44 per cent of those who drank while pregnant had children with conduct disorder, compared to 20 per cent of mothers with alcoholism who didn’t drink during pregnancy.

These findings show that women are better off completely avoiding alcohol during pregnancy, Dr Disney concludes. “I hope that the sacrifice of giving up drinking for the nine months of pregnancy will be worth it in the long run for the payoff of having an easier and better behaved teenager,” she said.

Reuters Health

Source: Paediatrics, December 2008.