The following is a summary of “Effect of asthma management with exhaled nitric oxide versus usual care on perinatal outcomes” published in the November 2022 issue of Respiratory by Murphy et al.


Exacerbations of asthma during pregnancy have been linked to negative consequences for both mother and child. Our study’s primary objective was to evaluate the efficacy of standard asthma care with that of care based on fractional exhaled nitric oxide (FENO) in predicting and enhancing fetal and neonatal outcomes. Adjusting asthma treatment based on exhaled nitric oxide and symptoms every 6-12 weeks was compared to standard care in the Breathing for Life Experiment, a randomized controlled trial in 6 hospital prenatal clinics across the country (no treatment adjustment as part of the trial). 

The primary outcome was a combination of preterm birth, small for gestational age (SGA), perinatal mortality, and neonatal hospitalization as determined by medical records. Incidences of asthma flare-ups in mothers were a secondary outcome. Blinded outcome assessment and statistical analysis were combined with a stratified random allocation scheme based on the study site and self-reported smoking status to get the results (intention to treat). A total of 601 pregnant women with active asthma were enrolled in the study’s intervention group, whereas 599 were assigned to the control group (608 newborns) (615 infants). Preterm birth (OR 1.14, 95% CI 0.78-1.68), SGA (OR 1.06, 95% CI 0.80-16.5), perinatal mortality (OR 3.62, 95% CI 0.80-16.5), neonatal hospitalization (OR 1.24, 95% CI 0.89-1.72).

Maternal asthma exacerbations requiring hospital admission or emergency department presentation (OR 1.24, 95% CI 0.89-1.72) did not differ significantly between groups. Pharmacotherapy for asthma that was guided by FENO and administered by a nurse or midwife in a prenatal clinic did not result in better birth outcomes.

Source: erj.ersjournals.com/content/60/5/2200298