Clinical features of asthma exacerbations (mild and severe) during pregnancy
| Never smokers | Ex-smokers | Current smokers | p Value | |
| Events/person | 1.5 (1–2) | 2 (1–3) | 2 (1–3) | NS |
| Lung function at first exacerbation | n=13 | n=15 | n=18 | |
| FENO at exacerbation (ppb) | 23.7 (17.9–39.2)* | 22.7 (15.8–75.7)* | 10.7 (6.8–18.2) | 0.017 |
| Increase in FENO (exacerbation) compared with lowest (Δppb) | 13.6 (6.1–16.6) | 6.8 (2.3–47.0) | 0.8 (0–5.8) | NS |
| ECO at exacerbation (ppm) | 1 (1–2)* | 1 (1–1)* | 8 (4–19) | 0.0001 |
| FEV1/FVC (%) at exacerbation | 80.2 (75.0–89.4) | 78.0 (70.2–83.7) | 81.3 (74.7–86.1) | NS |
| % predicted FEV1 at exacerbation | 96.0 (84.7–102.6) | 86.8 (77.8–106.2) | 88.6 (77.2–103.0) | NS |
| % predicted FVC at exacerbation | 98.1 (91.2–105.1) | 91.9 (88.3–113.3) | 100.2 (84.8–105.5) | NS |
| ACQ score at first exacerbation | n=21 | n=24 | n=21 | |
| Overall ACQ6 at exacerbation | 1.17 (0.83–2.17) | 1.67 (1.08–2.75) | 2.17 (1.67–2.67) | NS |
| Increase in ACQ (exacerbation) compared with lowest (ΔACQ) | 1 (1–1) | 1 (0–2) | 2 (1–2) | NS |
| ACQ6 Domain 1 (Night waking) | 1 (0–3) | 2 (1–3) | 2 (1–3) | NS |
| ACQ6 Domain 2 (Morning symptoms) | 2 (1–2) | 2 (2–3) | 2 (2–3) | NS |
| ACQ6 Domain 3 (Activity limitation) | 1 (0–2) | 0.5 (0–2) | 2 (1–3) | NS |
| ACQ6 Domain 4 (Shortness of breath) | 2 (1–3) | 2 (1–3.5) | 3 (2–3) | NS |
| ACQ6 Domain 5 (Wheeze) | 1 (0–2) | 2 (1–3) | 2 (2–4) | NS |
| ACQ6 Domain 6 (Beta agonist use) | 2 (1–2) | 1 (1–2) | 2 (1–3) | NS |
| Symptoms during exacerbation | n=13 | n=15 | n=18 | |
| Night waking (nights in past week) | 3 (0–6) | 3 (2–7) | 3.5 (2–5) | NS |
| Morning symptoms (mornings in past week) | 3 (2–4) | 4 (0–7) | 5.5 (3–7) | NS |
| Activity limitation (days in past week) | 2 (0–3) | 0 (0–2) | 2.5 (0–7) | NS |
Values are median (IQR) or n (%) of subjects in each group.
↵* Post hoc test significant p<0.017 vs current smokers.
ACQ, asthma control questionnaire; ECO, exhaled carbon monoxide; FENO, fractional exhaled nitric oxide; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; NS, not significant.