Airway size in rats with a low birth weight is more varied than those born at a normal weight—which Western Australian scientists think may play a role in the development of asthma in small babies.

Around 2.5 million Australians suffer from asthma, causing breathing difficulties when they’re experiencing an attack. But around 5-10 per cent of them suffer severe asthma, meaning they have difficulty breathing most, or all, of the time.

These people have a thicker muscle in the airways, which is a pathological feature of asthma.

“Reduced oxygen supply to the womb results in smaller babies. We know that small babies have an increased risk of developing asthma when they get older, but we don’t know why,” says the leader of the research, Kimberley Wang, previously of the Telethon Kids Institute and now at the University of Western Australia.