Teenagers whose mothers drank early in pregnancy are more likely to become unruly, aggressive and badly behaved, researchers claim.
According to their study, the risk of anti-social behavior rose threefold among 16-year-olds whose mothers drank as little as one alcoholic drink a day during the first three months of pregnancy, reports the media.
The U.S. study of almost 600 youngsters analyzed rates of 'conduct disorder' at regular intervals from their birth.
Conduct disorder was defined as a pattern of behavioral problems that included aggression towards people and animals, destruction of property, deceitfulness, theft and serious rule-breaking.
The risk of 'lifetime' bad behavior patterns went up threefold with one or more drinks a day compared with drinking less, or abstaining. There was no extra risk linked to drinking at a later stage in the pregnancy.
Dr Cynthia Larkby, from the University of Pittsburgh, monitored 592 children from birth to age 16, half of whom were African-American with the other half white.
Information was collected about the drinking habits of the children's mothers, including quantity, frequency and the pattern of alcohol use.
"From a clinical perspective, prenatal alcohol exposure should be considered as another risk for conduct disorder," the researchers said.
The study appears in the Journal of the American Academy of Child and Adolescent Psychiatry.