Associations between prenatal exposure to antibiotics (users versus nonusers) and wheezing outcomes in children aged ≤18 months
| Outcomes | Cases | Exposed cases | RRcrude | RRadj1# | RRadj2¶ | RRadj3+ |
| First trimester | ||||||
| Ever-wheezing | 750 | 60 (8.0) | 1.25 (1.00–1.57) | 1.14 (0.91–1.43) | 1.07 (0.85–1.35) | 1.02 (0.80–1.30) |
| Recurrent wheezing | 130 | 12 (5.7) | 1.49 (0.84–2.66) | 1.25 (0.70–2.24) | 1.09 (0.60–1.98) | 0.99 (0.54–1.82) |
| Third trimester | ||||||
| Ever-wheezing | 877 | 74 (8.4) | 1.34 (1.10–1.64) | 1.25 (1.02–1.52) | 1.18 (0.95–1.46) | 1.12 (0.90–1.39) |
| Recurrent wheezing | 158 | 24 (15.2) | 2.72 (1.80–4.11) | 2.36 (1.57–3.54) | 2.25 (1.44–3.53) | 2.09 (1.32–3.29) |
Data are presented as n, n (%) or risk ratio (RR) (95% CI). RRadj: adjusted risk ratio. #: adjusted for maternal educational level, maternal age at birth, smoking in pregnancy, siblings, paracetamol use in pregnancy and maternal asthma or asthmatic bronchitis; ¶: adjusted as RRadj1 and for maternal respiratory infections (bronchitis, flu, throat infections, otitis, sinusitis and common cold); +: adjusted as RRadj2 and for other maternal infections (urinary tract infections and vaginal infections) and fever >38°C.