TABLE 3

Adjusted Differences in BMI and Height z Scores at Ages ∼7 and ∼11 Years According to Prenatal or Early Postnatal SHS Exposure, Classified According to Postnatal Smoking Hygiene

MeasureSHS ExposureLinear Regression for Mean (N = 6710)Quantile Regression for 85th Percentile (N = 6519)
7 y11 y7 y11 y
nDifference, Mean (95% CI)anDifference, Mean (95% CI)aDifference, Mean (95% CI)bDifference, Mean (95% CI)b
BMINo prenatal and no postnatal SHS exposure1921Reference1871ReferenceReferenceReference
Only prenatal SHS exposure from nonpaternal sources21330.07 (−0.01 to 0.15)20660.06 (−0.02 to 0.14)0.12 (−0.04 to 0.27)0.11 (0.002 to 0.22)
No prenatal SHS exposure and any postnatal household smoker smoked ≥3 m from infant3280.11 (−0.03 to 0.26)3170.06 (−0.10 to 0.23)0.23 (−0.14 to 0.60)0.17 (−0.05 to 0.38)
No prenatal SHS exposure and any postnatal household smoker smoked <3 m from infant830.07 (−0.20 to 0.35)840.08 (−0.22 to 0.38)0.16 (−0.43 to 0.75)0.13 (−0.22 to 0.49)
Any prenatal SHS exposure and any postnatal household smoker smoked ≥3 m from infant16650.09 (0.01 to 0.17)16170.13 (0.04 to 0.22)0.07 (−0.08 to 0.22)0.13 (0.02 to 0.24)
Any prenatal SHS exposure and any postnatal household smoker smoked <3 m from infant5810.03 (−0.08 to 0.15)5650.09 (−0.04 to 0.22)0.19 (−0.01 to 0.38)0.13 (−0.02 to 0.27)
HeightNo prenatal and no postnatal SHS exposure1921Reference1871ReferenceReferenceReference
Only prenatal SHS exposure from nonpaternal sources21330.02 (−0.04 to 0.07)20660.02 (−0.05 to 0.08)0.001 (−0.09 to 0.09)0.03 (−0.07 to 0.12)
No prenatal SHS exposure and any postnatal household smoker smoked ≥3 m from infant3280.05 (−0.06 to 0.16)3170.04 (−0.08 to 0.16)0.02 (−0.14 to 0.18)0.01 (−0.19 to 0.22)
No prenatal SHS exposure and any postnatal household smoker smoked <3 m from infant830.07 (−0.14 to 0.29)840.17 (−0.06 to 0.40)0.14 (−0.30 to 0.58)0.27 (−0.30 to 0.85)
Any prenatal SHS exposure and any postnatal household smoker smoked ≥3 m from infant1665−0.01 (−0.07 to 0.05)16170.00 (−0.07 to 0.07)−0.01 (−0.10 to 0.08)0.01 (−0.10 to 0.12)
Any prenatal SHS exposure and any postnatal household smoker smoked <3 m from infant581−0.01 (−0.10 to 0.08)5650.03 (−0.07 to 0.13)0.02 (−0.12 to 0.16)0.09 (−0.06 to 0.24)
  • Calculations were adjusted for gender, birth order, highest parental education, mother's place of birth, pubertal status (for 11 years), highest parental occupation, household income per person, breastfeeding history, and number of hospital admissions attributable to infections at 0 to 6 months.

  • a Differences in z scores for mean relative to 2007 growth references. At the age of 7.0 years, a 1-unit change in BMI z score is ∼1.7 kg/m2. At the age of 7.0 years, a 1-unit change in height z score is ∼5.4 cm. At the age of 11.0 years, a 1-unit change in BMI z score is ∼2.5 kg/m2. At the age of 11.0 years, a 1-unit change in height z score is ∼6.65 cm.

  • b Differences in z scores for 85th percentile relative to 2007 WHO growth references. At the age of 7.0 years, a 1-unit change in BMI z score is ∼2.25 kg/m2. At the age of 7.0 years, a 1-unit change in height z score is ∼5.35 cm. At the age of 11.0 years, a 1-unit change in BMI z score is ∼3.55 kg/m2. At the age of 11.0 years, a 1-unit change in height z score is ∼6.75 cm.