TABLE 1

Maternal and Child Characteristics in 4 Prenatal Nicotine Exposure Groups According to Tobacco Smoke and Use of NRT, the DNBC, 1996–2002

Mother and Child CharacteristicsMaternal Smoking and Use of NRT (%)
Unexposed (n = 46 660)NRT Users (n = 207)Smokers (n = 15 016)Smoking + NRT (n = 1245)
Primiparousa48.557.050.657.4
Social classb
 High-grade professionals and managers38.739.623.429.6
 Middle-grade professionals32.735.829.934.3
 Skilled workers, students26.122.239.731.7
 Unskilled workers, unemployed, social security2.62.47.04.4
Mother’s age, ya
 <254.31.09.87.0
 25–2932.924.334.430.4
 30–3441.849.036.637.9
 35–3918.220.916.621.0
 ≥402.94.92.63.8
Coffee consumption (cups per d)a
 061.138.740.331.4
 <1–434.748.841.445.9
 ≥54.212.618.322.7
Alcohol consumption (units per wk)a
 055.147.356.150.7
 <1–234.232.930.633.5
 3–410.018.811.714.1
 ≥50.711.71.8
≥1 Binge drinking episode during pregnancyb 22.328.033.435.3
Married or cohabitatinga,c98.698.194.895.4
Major concern about the birth and the child’s health while pregnantb 5.16.37.79.1
Child exposed to environmental tobaccoa,c 5.72.928.523.7
GAb
 <37 wks4.02.94.95.2
 37–40 wks86.985.986.085.4
 ≥41 wks9.111.29.19.4
BW <2500 gb 2.42.94.34.8
5 min Apgar score <7d0.600.60.7
Girlsa 49.043.049.245.9
Child never had formula milkc,e28.028.420.619.9
  • a Percentage of missing values for each covariate ≤0.1%.

  • b Percentage of missing values for each covariate ≤0.5%.

  • c Refers to the 6 months postpartum interview (all prenatal exposures were assessed in the second-trimester interview).

  • d Percentage of missing values for each covariate ≤1%.

  • e Percentage of missing values for each covariate ≤10%. One unit of alcohol corresponds to 12 g of alcohol.