London, October 01: Mothers who smoke during pregnancy put their children at greater risk of developing psychotic symptoms as teenagers, British scientists said.
Researchers from four British universities studied 6356 12-year-olds and interviewed them for psychotic-like symptoms such as hallucinations or delusions.
Around 19 per cent had mothers who smoked during pregnancy.
Just over 11 per cent, or 734 of the total group, had suspected or definite symptoms of psychosis.
Stanley Zammit, a psychiatrist at Cardiff University’s School of Medicine who led the study, said the more the mothers smoked, the more likely their children were to have psychotic symptoms.
“We can estimate that about 20 per cent of adolescents in this cohort would not have developed psychotic symptoms if their mothers had not smoked,” he said.
Despite countless studies flagging up the risks to babies, it was estimated that between 15 and 20 per cent of women in Britain smoked during pregnancy.
The researchers also found drinking during pregnancy was associated with increased psychotic symptoms, but only in children whose mothers had drunk more than 21 units of alcohol a week in early pregnancy.
The reasons for the link between maternal smoking and psychotic symptoms are not clear, but Dr Zammit and colleagues suggested that exposure to tobacco in the womb might affect a child’s impulsivity, attention or cognition.
They said more research was needed to investigate how exposure to tobacco in the womb affected children’s brains.
Only a few mothers in the study, which was published in the British Journal of Psychiatry, said they had smoked cannabis during pregnancy, and this was not found to have any significant link with psychotic symptoms.
—Agencies