Fine-tuning asthma meds during pregnancy

Both mothers and babies have better outcomes when asthma is well-managed

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Asthma medication often has to change when a woman becomes pregnant and FeNO testing can help doctors fine-tune the adjustments, according to new research.

Fractional exhaled nitric oxide (FeNO) testing is nothing new; it’s a one-minute breath test to measure eosinophilic inflammation in patients with asthma. But what researchers from The University of Newcastle have done is combine the results of the FeNO test with information about symptoms into a treatment algorithm.

And they’ve packaged this algorithm into an iPad app so that doctors can use it to make smart decisions about how to treat asthma during pregnancy.

“It’s as simple as inputting the woman’s smoking status, her FeNO level and her level of asthma control or her symptoms and the algorithm then makes the treatment decision based on that,” said Dr Vanessa Murphy, a postdoctoral scientist at The University of Newcastle who presented her research at the RANZCOG annual scientific meeting in Melbourne in October.

The team’s early research showed that using the FeNO-based approach to adjust asthma medication during pregnancy reduced the asthma exacerbation rate by 50%.

“[The algorithm] was also associated with a lower inhaled corticosteroid dose by the end of the study compared to women who had their treatment adjusted based on symptoms alone,” Dr Murphy said.

Both mothers and their babies had better outcomes when asthma was well-controlled during pregnancy, she said.

“When we followed up the babies from this study, the infants whose mothers had received this approach were 90% less likely to have recurrent bronchiolitis in the first 12 months of life,” she said.

“And they were 54% less likely to have doctor-diagnosed asthma themselves at preschool age.”

The reason the babies were protected against asthma if their mother’s asthma was controlled during pregnancy was unknown, she said.

But there were several possible mechanisms. “It may be that there are changes in the way of the fetal immune system is programmed. It might be more directly linked to the use of inhaled corticosteroids,” Dr Murphy said.

The FeNO breath test measures the amount of eosinophilic inflammation in the lungs. In some patients with asthma, airway inflammation is driven by high eosinophil levels, which can be reduced by taking inhaled corticosteroids (ICS).

In other patients with asthma, however, eosinophil levels are low and taking higher doses of ICS will not help manage their symptoms.

“So, when a woman has a high level of eosinophils, our treatment algorithm increases inhaled corticosteroids and when she has a low level, we decrease medication,” Dr Murphy said.

“We also added LABA when symptoms were uncontrolled. And in the mid-range we don’t make any changes. So, it’s a precise way of adjusting medication for her situation in her lungs.”

Dr Murphy’s research team has just completed recruitment for the ‘Breathing for Life’ trial, a randomised controlled trial to test FeNO-guided asthma management in clinic.