The Managing Asthma in Pregnancy study found regularly adjusting treatment of mothers’ asthma symptoms using a simple breath test during pregnancy halved the incidence of asthma in their children by the time they were between 4 and 6 years of age.

The University of Newcastle and Hunter Medical Research Institute study is the first to demonstrate a clear link between a mother’s adjusted asthma treatment and her child developing asthma.

The study’s findings are significant because asthma is the most common chronic disease affecting more than 10 per cent of pregnant women, lead researchers Professor Joerg Mattes and Dr Vanessa Murphy said.

“Implementation of this approach in clinical practice has the potential to reduce asthma rates among a group of children at high risk of developing the disease,” the study published this week in the Journal of Allergy and Clinical Immunology said.

The MAP study followed children born between February, 2008 and November, 2010 to asthmatic mothers who were divided into two groups, with one group of mothers treated in response to clinical symptoms, and the second group treated in response to exhaled nitrous oxide levels and clinical symptoms. The original group of babies included one set of triples and three sets of twins.

The study of 140 children, aged between four and six when followed up, found treating mothers in response to their exhaled nitrous oxide levels via a simple breath test reduced the odds of asthma in their children by the time they were ready for school by greater than 50 per cent.

Increasing treatment for asthmatic mothers also significantly reduced the risk of frequent wheezing and recurrent bronchiolitis in children and reduced medication use and emergency department visits for wheeze and asthma.

Children whose mothers have asthma are up to three times more likely to develop the condition.

In 2013 Newcastle mother Jodi Slinn told the Newcastle Herald she took part in the trial because of her daughter Olivia, then aged three.

The thought that Olivia might not have to go through asthma, as she had, was exciting, Mrs Slinn said.

She regularly underwent the nitrous oxide breath test during her pregnancy as part of the randomised trial and her daughter, by age three, showed no signs of having asthma.

Mrs Slinn said grew up always having to make sure her puffer was near by.

“It’s much nicer to think by controlling asthma in the pregnancy that Olivia might not have to worry about it and avoid going through that,” she said.