Drinking alcohol in the early stages of pregnancy could increase the chances of a child being unruly, aggressive and badly behaved once they reach teenage years, a study has claimed.
According to US researchers from the University of Pittsburgh, consuming just one drink a day in the first three months of pregnancy means there is three times the risk that the child will suffer from "conduct disorder" at the age of 16.
The disorder is recognised as a number of behavioural problems, including aggression towards people and animals, rule-breaking, destruction of property and deceitfulness or theft.
The study, which was led by Dr Cynthia Larkby, involved the monitoring of 592 children from the time they were born until they reached 16.
Information was collected about the drinking habits of the children's mothers, including quantity, frequency and the pattern of alcohol use.
The researchers found that teenagers exposed to an average of one or more alcoholic drinks a day in the womb were three times more likely to be diagnosed with conduct disorder than those whose mothers drank less or abstained.
However, the association was only significant when alcohol was consumed during the first three months of pregnancy.
The scientists wrote in the Journal of the American Academy of Child and Adolescent Psychiatry: "From a clinical perspective, prenatal alcohol exposure should be considered as another risk for conduct disorder.
"The next steps in research should be to define the interactions between prenatal exposures, environmental factors, and heritability. This would allow a more complete picture of the relations between prenatal alcohol exposure and conduct disorder."
It was already known that heavy drinking during pregnancy can result in foetal alcohol syndrome, which may lead to stunted growth, heart defects, and impaired brain development.