FENO Intervention Reduces Asthma in Offspring of Mothers With Asthma

Pregnant woman with asthma holding inhaler
Pregnant woman with asthma holding inhaler
Offspring of mothers with asthma had a reduced odds of having asthma themselves when the mothers were treated with a strategy guided by fraction of exhaled nitric oxide.

Offspring of women with asthma during pregnancy had a >50% reduced odds of having asthma by the ages of 4 to 6 years when the mothers were treated using a strategy guided by fraction of exhaled nitric oxide (FENO), according to a study published in the Journal of Allergy and Clinical Immunology.

In the single-center double-blind randomized controlled trial, Managing Asthma in Pregnancy (MAP; Australian New Zealand Clinical Trials Registry Number 12607000561482) in Newcastle, Australia, a treatment algorithm using FENO in combination with asthma symptoms (FENO group) was compared against a treatment algorithm using clinical symptoms only (clinical group) in pregnant women with asthma. The children of participants in this study who were born between February 6, 2008, and November 25, 2010 were subsequently recruited to the Growing into Asthma study. 

Follow-up visits were conducted for collection of biosamples to assess children at 12 months (n=146) and at 4 to 6 years of age (n=140), during which study personnel were blinded as to which treatment group the mother was allocated to during pregnancy. Parent(s)/carer(s) completed the International Study of Asthma and Allergies in Childhood core questionnaire, and clinical examinations of each child were performed to confirm the appropriateness of a doctor diagnosis of asthma according to national asthma guidelines. Buccal swabs from participating children were collected at a follow-up visit and used to extract DNA. Researchers performed genotyping using the TaqMan (Applied Biosystems, Thermo Fisher Scientific) assays, and 5 previously reported childhood onset asthma-associated single nucleotide polymorphisms at locus 17q21 were genotyped (rs8069176, rs7216389, rs8076131, rs9303277, rs2290400).

The rate of asthma observed in the offspring of mothers from the FENO group was significantly lower compared with offspring of mothers in the clinical management group (unadjusted odds ratio [OR], 0.46; 95% CI, 0.22-0.96; P =.037). Usage of short-acting β-agonists in the last 12 months to manage cough, wheeze, or asthma was also significantly lower in the offspring of mothers in the FENO group compared with the clinical group (unadjusted OR, 0.49; 95% CI, 0.25-0.97; P =.042), as was attending the emergency department in the last 12 months for wheezing or asthma (unadjusted OR, 0.17; 95% CI, 0.04-0.76; P =.021) and frequent bronchiolitis (>1 episode; unadjusted OR, 0.21; 95% CI, 0.07-0.65; P =.007).

Limitations of this study included a small cohort and parent-reported asthma symptoms. A key strength of this study, however, is “the randomized, controlled design of the MAP study’s asthma management intervention along with comprehensive prospective data collection on asthma exacerbations, medications, and FENO levels throughout pregnancy,” the researchers wrote.

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They concluded that these results are clinically relevant and demonstrate that FENO-guided asthma management during pregnancy can reduce rates of asthma in offspring.

Disclosures: One author declares affiliations with the pharmaceutical industry. Please refer to original reference for a complete list of authors’ disclosures.


Morten M, Collison A, Murphy VE, et al. Managing Asthma in Pregnancy (MAP) trial: FENO levels and childhood asthmaJ Allergy Clin Immunol. 2018;142(6):1765-1772.