Joint effects of environmental tobacco smoke (ETS) and in utero exposure to maternal smoking on lung function level, percentage change and 95% confidence intervals (95% CI), Children's Health Study, 1993 (n = 3357)
| % Change (95% CI) | |
| FEV1 | |
| None | – |
| ETS only | −0.1 (−1.1 to 1.0) |
| In utero only | −0.1 (−2.8 to 2.6) |
| In utero + ETS | −1.1 (−3.9 to 2.0) |
| FVC | |
| None | – |
| ETS only | −0.5 (−1.4 to 0.5) |
| In utero only | 2.1 (−0.4 to 4.6) |
| In utero + ETS | −1.4 (−4.1 to 1.4) |
| PEFR | |
| None | – |
| ETS only | −0.3 (−1.8 to 1.2) |
| In utero only | 1.7 (−2.2 to 5.7) |
| In utero + ETS | −3.6 (−5.3 to −1.2) |
| MMEF | |
| None | – |
| ETS only | 0.2 (−2.1 to 2.6) |
| In utero only | −3.6 (−9.3 to 2.5) |
| In utero + ETS | −4.6 (−7.2 to 2.1) |
| FEF75 | |
| None | – |
| ETS only | 0.7 (−2.3 to 3.8) |
| In utero only | −7.6 (−14.8 to 0.2) |
| In utero + ETS | −5.6 (−8.8 to −2.2) |
For definitions see table 3.