FeNO and pregnancy
Asthma is the most common respiratory condition affecting pregnant women.1 For some women, asthma symptoms may worsen during pregnancy, potentially leading to an increased risk of exacerbations.2 In this article, we will explore how FeNO-guided asthma management can be used to support women throughout pregnancy to help improve control and outcomes.
Last updated: March 2026
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One study showed that adjusting treatment based on FeNO resulted in a 50% reduction in exacerbations compared to symptom-based management alone.
It is estimated that asthma affects up to 12% of pregnant women.1 This can result in heightened risk of complications when not adequately controlled.2 A recent study has suggested that up to two-thirds of pregnant women may experience uncontrolled asthma, with around 64% demonstrating incorrect inhaler technique.1
During pregnancy, it is important that a patient’s asthma is monitored to maintain control.1-3 FeNO testing is a safe and effective way to monitor airway inflammation, helping to spot early signs of reduced control – helping to inform treatment decisions and keep your patients on track.4,5
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FeNO-guided management has emerged as a key tool to help reduce exacerbations during pregnancy.6 One study showed that adjusting treatment based on FeNO, resulted in a 50% reduction in exacerbations compared to symptom-based management alone.6 This approach led to more women being prescribed ICS at lower doses and reduced reliance on oral corticosteroids (OCS) and reliever medication.6
Additionally, another study found that FeNO-guided management helped women feel safe in their asthma care and reassured that their condition was under control.7 It is suggested that the benefits of a FeNO-guided approach extend past pregnancy, with evidence suggesting that children born to mothers managed under a FeNO-guided asthma approach also had longer-term benefits to their respiratory health.7
Clinical guidelines recommend that women with asthma be reviewed as normal and then more frequently during pregnancy – typically every four weeks.3,6 This provides a suitable opportunity for FeNO monitoring, ensuring that you can have objective data on how your patient’s asthma is doing throughout their pregnancy.
A FeNO-guided management approach can help safely reduce ICS doses where appropriate and reduce the need for systemic steroids - minimising unnecessary medication exposure during pregnancy.7 It can also be used to monitor adherence and inhaler technique, ensuring patients are taking their medication as prescribed.4
Learn more about FeNO testing with these recomendations:
Non-invasive and easy way to monitor airway inflammation6
Safely guide treatment options 3
Helps identify non-adherence and assess inhaler technique 8
Can help to reduce exacerbations and OCS reliance 6
Offers reassurance to expectant mothers 7
Can support better outcomes for mother and child 7
NIOX® provides rapid, non-invasive FeNO measurements at the point-of-care, with only one test needed for an accurate result.8 Simple to incorporate into routine reviews, it enables regular monitoring airway inflammation that can identify poor asthma control and predict responsiveness of treatment options.4,9
When incorporated into guideline-recommended four-weekly reviews during pregnancy, FeNO monitoring that has been associated with fewer exacerbations and lower ICS exposure.6
Effective asthma management in pregnancy requires maintaining control while using the lowest effective ICS dose.3 FeNO-guided care offers a practical, precision-based treatment strategy to managing airway inflammation and has shown to improve outcomes for mother and child compared with symptom-guided management alone.3,4
To learn more about how FeNO can support safe and confident ICS optimisation in practice, read our article on reducing ICS with FeNO-guided management, or access our other educational resources and discover how FeNO by NIOX® can help support your asthma care.
Discover our latest FeNO webinar today.
At NIOX® we are passionate about providing excellent support and training.
1. Ibrahim WH et al. Asthma knowledge, care, and outcome during pregnancy: The QAKCOP study. Chronic Respiratory Disease. 2018;16. Available at; https://doi.org/10.1177/1479972318767719
2. Lee, B et al. Pregnancy, asthma and exacerbations: a population-based cohort. European Respiratory Journal. 2025. Available at; https://doi.org/10.1183/13993003.01327-2025
3. Couillard, S et al. Asthma in pregnancy: An update. Obstetric medicine. 2021;14(3):135–144. Available at; https://doi.org/10.1177/1753495X20965072
4. Loewenthal L et al. FeNO in asthma. Semin Respir Crit Care Med. 2022;43:635-645
5. Bonini M et al. The role of Fraction Exhaled Nitric Oxide (FeNO) in asthma management: an Italian consensus statement on clinical and economic aspects. Multidisciplinary Respiratory Medicine. 2025;20(2025):1-8.
6. Murphy VE. Managing asthma in pregnancy. Breathe. 2015;11(4): 258-267. Available at; https://doi.org/10.1183/20734735.007915
7. McLaughlin K et al. The acceptability and feasibility of implementing a Fractional exhaled Nitric Oxide (FeNO)-based asthma management strategy into antenatal care: The perspective of pregnant women with asthma. Midwifery. 2020;88. Available at; https://doi.org/10.1016/j.midw.2020.102757
8. Hanania NA et al. Measurement of fractional exhaled nitric oxide in real-world clinical practice alters asthma treatment decisions. Ann Allergy Asthma Immunol. 2018;120(4):414-418.
9. Menzies-Gow A et al. Clinical utility of fractional exhaled nitric oxide in severe asthma management. Eur Respir J. 2020;55(3):1901633.
