Treatable Traits and Asthma Control: a Prospective Study in Pregnancy.

BACKGROUND: The treatable traits (TTs) approach has emerged as a promising strategy for managing asthma, but its application in pregnant women remains underexplored. OBJECTIVE: To explore the effect of a TT-based intervention on asthma outcomes in pregnant women. METHODS: This prospective study enrolled 62 non-pregnant and 37 pregnant women with asthma. Multidimensional assessment identified pulmonary, extrapulmonary, and behavioral and risk factor TTs. Participants then received a 12-week multidisciplinary intervention tailored to TTs. We assessed TTs, Asthma Control Questionnaire-5 (ACQ-5), and the cough evaluation test at baseline and after the intervention. RESULTS: Total TTs significantly decreased from a median (interquartile range) of 5.0 (3.0-6.0) to 2.0 (2.0-3.0) overall (P < .001), with consistent improvements in both subgroups. Results from ACQ-5 improved from 0.8 to 0.2 (P < .001), and the cough evaluation test from 12.0 to 6.0 (P < .001). Changes in TTs showed a strong positive correlation with improvements in ACQ-5 in the overall cohort (ρ = 0.69; P < .001), which remained robust in both subgroups. Multivariable regression identified ΔTTs as an independent predictor of postintervention ACQ-5 (β = -0.67; P < .001). Mediation analysis further revealed a significant indirect effect of baseline TTs on asthma improvement through ΔTTs (effect = 0.13; 95% CI, 0.08-0.19), supporting a causal mediation pathway. Baseline between-group comparisons showed no significant differences in most TTs after adjustment. All pregnant women delivered safely, with no intervention-related serious adverse events. CONCLUSIONS: In this single-arm study, a trait-guided intervention was associated with reduced TTs and improved asthma control, with TTs reduction mediating the improvement. The approach appeared safe in pregnancy, but randomized control trials are needed.