FENO-based asthma management in prenatal care is not effective for improving perinatal outcomes.
Asthma is one of the most common chronic disorders that affect pregnant women. Asthma affects 8–12% of pregnant women globally, with exacerbations requiring medical intervention affecting 20–45% of these women. Pregnancy-related asthma exacerbations are connected with worse perinatal outcomes. This study was published in the European Respiratory Journal and aimed to assess if fractional exhaled nitric oxide (FENO)-based asthma therapy improved perinatal outcomes compared to standard care.
The Breathing for Life Trial (BLT) was a multicenter, parallel-group, randomized controlled trial conducted in six hospital prenatal clinics that compared asthma therapy guided by FENO (modification of asthma treatment based on exhaled nitric oxide and symptoms every 6–12 weeks) versus standard care (no treatment adjustment as part of the trial). Using hospital records, the primary outcome was a composite of unfavorable perinatal events (preterm birth, small for gestational age (SGA), perinatal mortality, and neonatal hospitalization). Secondary results included asthma exacerbations in mothers. Participants were assigned to study groups (intention to treat) based on concealed random allocation, stratified by study site and self-reported smoking status, along with blinded outcome evaluation and statistical analysis.
In this study, 599 pregnant women with asthma were assigned to the control group (608 newborns), while 601 pregnant women with asthma were assigned to the intervention group (615 infants). There were no significant differences between groups for the primary composite perinatal outcome, preterm birth, SGA, perinatal mortality, neonatal hospitalization, or maternal asthma.
FENO-guided asthma medication administered in a prenatal clinic by a nurse or midwife did not improve perinatal outcomes. Neither the primary outcome nor its components (preterm birth, SGA, neonatal hospitalization, or perinatal mortality) nor birth weight, which was numerically greater in the FENO group, differed significantly across groups. The FENO-based treatment algorithm had no meaningful influence on maternal asthma exacerbations, which were numerically lower in the FENO group than in the standard care group.
This study did not support the use of FENO-based management in antenatal care to improve perinatal outcomes.
Murphy, V. E., Jensen, M. E., Holliday, E. G., Giles, W. B., Barrett, H. L., Callaway, L. K., Bisits, A., Peek, M. J., Seeho, S. K., Abbott, A., Robijn, A. L., Colditz, P. B., Searles, A., Attia, J., McCaffery, K., Hensley, M. J., Mattes, J., & Gibson, P. G. (2022). Effect of asthma management with exhaled nitric oxide versus usual care on perinatal outcomes. European Respiratory Journal, 60(5). https://doi.org/10.1183/13993003.00298-2022