UK and US researchers have said that mothers that smoke are more likely to have children with behavioural problems than those that do not.
The team believe that smoking while pregnant can damage the structure of the foetus’ brain as it develops and said that the problems could be noticed in children as young as three. The scientists, from the universities of Hull, York and Illinois based their conclusions on studies of more than 14,000 mother and child pairs who took part in the Millennium Cohort Study.
After rating the mothers as light or heavy smokers according to how many cigarettes they smoked a day, they were asked to rate their children’s behaviour using a questionnaire named Strengths and Difficulties, which focused on hyperactivity and behavioural issues.
The team accounted for elements likely to influence the results, such as socioeconomic status, the mother’s age when she conceived, parenting issues and family stability.
They discovered that heavy smokers were 80% more likely to give birth to boys with behavioural problems, while light smokers were 44% more likely to have boys with such problems. There was also an increase in the chance that their children would have hyperactivity or attention deficit disorders.
With girls, smoking was associated with behaviour problems but not with hyperactivity.
Professor Alan Maryon Davies, who is president of the Faculty of Public Health, said that as there are 4,000 toxic substances in cigarette smoke, it was very possible that these would pass into the brain of the foetus and affect brain chemisty.
The findings have been published in the Journal of Epidemiology and Community Health.