Asthma control in pregnancy reduces bronchiolitis risk

Infants born to mothers with asthma have more bronchiolitis and croup and are also more likely to develop asthma later in life. 

However, the effect of asthma management during pregnancy on these outcomes has so far been unknown.

The Managing Asthma in Pregnancy (MAP) study, to be published tomorrow in the BMJ Journal Thorax, provided asthma treatment to two groups based on monitoring either their clinical symptoms or airway inflammation using a marker known as Fraction of Exhaled Nitric Oxide (FeNO). 

Of the 220 women in the study, 146 babies were followed up at 12 months and at four years of age.

For the women managed with FeNO, the rate of asthma exacerbation was halved. 

Of their babies, only 1.5% had recurrent bronchiolitis in the first year of life compared to 16% for mothers managed according to symptoms. 

For croup, there was an almost 10-fold reduction in incidence rate for the FeNO group