Experts have discovered further evidence that heavier women could be more likely to have children who suffer wheezing or asthma.

Those who are overweight or obese before they become pregnant are between 20 per cent and 30 per cent more likely to have teenagers who wheeze or have asthma, or who suffered either condition when they were younger.

The heaviest women in the study – who weighed between 62 kilo and 130 kilo – were much more likely to have children with wheezing symptoms than those who were of a lower weight.

Marjo-Riitta Jarvelin, professor and study author from Imperial College London, said there was a linear association between increasing maternal weight and increased risk of asthma symptoms.

Furthermore, the risk was strong when experts looked at body mass index – which takes height into account – rather than just how much women weighed.

“As BMI increases, there is a linear association,” Prof. Jarvelin said.

“The heavier the women, the more the risk of wheezing and asthma-like symptoms.

“The children of obese women who have a history of allergy also have a much higher risk of wheezing.

“There is over 3.5 times higher risk of having wheezing, and for current wheezing the risk was over four times higher.”

While the researchers say the study does not definitely show that obesity causes respiratory symptoms among teenagers, they point to other research with similar findings.

And they conclude that rising rates of asthma “may be partly related to the rapid rise in obesity in recent years”.

Previous studies have suggested that children of overweight mothers are exposed to increased levels of pro-inflammatory factors in the womb, which could influence their asthma risk.

The latest study, published in the Journal of Epidemiology and Community Health, involved almost 7,000 15- and 16-year-olds born in 1985 and 1986 in northern Finland.