Table 2

Proportions with wheeze by average daily ETS and number of cigarettes smoked by mother during pregnancy

without wheeze
Number with wheeze
Maternal smoking during pregnancy
 1 to 9 cigarettes per day421154(26.8)
 10 to 19 cigarettes per day442176(28.5)
 20 or more cigarettes per day14455(27.6)
ETS exposure
 <1 hour per day1187361(23.3)
 1 to 2 hours428135(24.0)
 2 to 4 hours322117(26.7)
 >4 hours22785(27.2)