28 June 2006

Smoking while pregnant increases the chances of having fat or obese children, research shows.

Australian women who smoke throughout pregnancy were 42 per cent more likely to have their offspring obese by age 14 years compared to mums who didn’t smoke, according to the University of Queensland study.

The risk of having overweight children was 31 per cent.

Lead researcher and child obesity expert, Dr Abdullah Al Mamun from UQ’s School of Population Health, said the findings were another incentive for pregnant women not to smoke as it was unhealthy and also linked to child behavioural problems.

Dr Mamun said 20 per cent of Australian mums smoked during pregnancy and while some women who smoked were thin, smoking had the opposite effect on their children.

“Although the percentage of smoking in the general population is declining, the rate of this is slowest among women of childbearing age,” Dr Mamun said.

“In the western world about 30 per cent of women of child bearing age currently smoke and two thirds of these women will continue to smoke during pregnancy.

“Smokers are still thinner than non-smokers in general but maternal in utero smoking has many negative consequences across the life of their offspring and obesity is one of them.”

The study was based on data from 3253 children born in Brisbane between 1981 and 1984, who took part in the Mater Hospital-University of Queensland Study of Pregnancy.

Researchers noted mothers’ smoking habits, their children’s levels of child fatness or obesity, their diet, how much TV they watched, physical activity and if they were breastfed.

Most children ate fast food at least two days per week and played sport between four and seven times a week but most watched about five hours of television per day.

Dr Mamun said more work was needed to pinpoint which of the 4000 chemicals in cigarette smoke could influence appetite and weight gain.

He said this was the first long-term study to examine the mums who smoked before, after and during pregnancy and diet and physical activity.

The study was funded by the National Health and Medical Research Council of Australia and has been published in the American Journal of Epidemiology.

Dr Mamun’s paper was co-written, with Mater and University of Bristol researchers and fellow UQ researcher and Mater Study founder, Professor Jake Najman.

Media: Dr Mamun (07 3346 4689, 0431 029 273) or Miguel Holland at UQ Communications (3365 2619)