Maternal smoking | Caffeine consumption | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Nil | 1–800 mg/24 h | > 800 mg/24 h | Total | ||||||||||
n | % | n | % | n | % | n | % | ||||||
Nil | 123 | 22.7 | 413 | 76.2 | 6 | 1.1 | 542 | 100 | |||||
1–4 cigarettes/day | 24 | 19.7 | 92 | 75.4 | 6 | 4.9 | 122 | 100 | |||||
5–9 cigarettes/day | 8 | 9.5 | 64 | 76.2 | 12 | 14.3 | 84 | 100 | |||||
10–14 cigarettes/day | 1 | 10 | 9 | 90 | 0 | 0 | 10 | 100 | |||||
>15 cigarettes/day | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 100 |
χ2 = 48.6; degrees of freedom (df) = 6; p < 0.001.