Proportions with wheeze by average daily ETS and number of cigarettes smoked by mother during pregnancy
| Number without wheeze | Number with wheeze | |||
|---|---|---|---|---|
| No. | % | |||
| Maternal smoking during pregnancy | ||||
| None | 5685 | 1484 | (20.7) | |
| 1 to 9 cigarettes per day | 421 | 154 | (26.8) | |
| 10 to 19 cigarettes per day | 442 | 176 | (28.5) | |
| 20 or more cigarettes per day | 144 | 55 | (27.6) | |
| ETS exposure | ||||
| Never | 4425 | 1120 | (20.2) | |
| <1 hour per day | 1187 | 361 | (23.3) | |
| 1 to 2 hours | 428 | 135 | (24.0) | |
| 2 to 4 hours | 322 | 117 | (26.7) | |
| >4 hours | 227 | 85 | (27.2) | |
| “Always” | 103 | 51 | (33.1) | |