Screening for asthma among women referred for fertility treatment using a symptom questionnaire and fractional exhaled nitric oxide.

Abstract

Introduction: Asthma, a highly prevalent disorder among women of reproductive age, is associated with infertility and adverse pregnancy outcomes. Well-controlled asthma likely improves fertility and pregnancy outcomes, yet asthma is underdiagnosed. Therefore, we evaluated the value of the 'Life Quality Test (LQT)' from the American College of Asthma, Allergy and Immunology and fractional exhaled nitric oxide (FeNO) as a screening tool for current asthma among women referred for fertility treatment, as they may benefit from further assessment.

Methods: A cross-sectional observational study was set up within the PRO-ART study. Women referred for fertility treatment at four Danish hospitals completed the LQT-survey. Those with affirmative responses were invited for a screening visit with spirometry, bronchial provocation, and FeNO measurement. Asthma diagnosis was based on bronchial provocation. Associations between asthma, FeNO, and LQT-scores were assessed using logistic regression. A grid-search algorithm identified thresholds for an effective screening tool.

Results: Of 188 women screened, 119 (63.3%) had asthma, of whom 47 (39.4%) had no previous asthma diagnosis. FeNO alone was weakly predictive (OR 1.04, p = 0.036), while LQT-scores were stronger predictors for asthma (OR 1.40, p < 0.001). Combined, FeNO and LQT-scores revealed good predictive value (AUC = 0.82). A screening algorithm with combined criteria of LQT ≥ 7, FeNO ≥ 25 ppb, or 5 ≤ LQT < 7 with FeNO 12-25 ppb achieved 87.9% sensitivity and 55.4% specificity.

Conclusion: Undiagnosed asthma is common among women referred for fertility treatment. Combining FeNO and LQT-score provides a feasible, non-invasive screening method for probable asthma, warranting validation in larger cohorts.