Effects of Tobacco Smoking in Pregnancy on Offspring Intelligence at the Age of 5
Table 4
Maternal smoking in pregnancy and WPPSI-Ra subtest raw scores.
Avgerage number of cigarettes/day
Unadjusted
Adjusted for core confoundersb
Adjusted for potential confoundersc
Mean score
Mean difference (95% CI)
Mean difference (95% CI)
Mean difference 95% CI
Information
0
19.3
Reference
Reference
Reference
1–9
19.0
−0.3 (−0.9, 0.3)
−0.1 (−0.6, 0.5)
−0.1 (−0.7, 0.5)
10+
18.7
−0.6 (−1.1, 0.0)
−0.2 (−0.7, 0.4)
−0.1 (−0.7, 0.5)
Vocabulary
0
21.1
Reference
Reference
Reference
1–9
20.6
−0.5 (−1.6, 0.6)
0.0 (−1.0, 1.0)
0.0 (−1.1, 1.0)
10+
20.8
−0.3 (−1.3, 0.6)
0.6 (−0.3, 1.5)
0.7 (−0.3, 1.8)
Arithmetic
0
14.9
Reference
Reference
Reference
1–9
14.3
−0.6 (−1.1, 0.2)
−0.3 (−0.9, 0.2)
−0.3 (−0.9, 0.3)
10+
14.2
−0.7 (−1.2, 0.0)
−0.1 (−0.8, 0.5)
−0.1 (−0.8, 0.6)
Object assembly
0
23.6
Reference
Reference
Reference
1–9
23.3
−0.3 (−1.2, 0.7)
0.0 (−0.9, 0.8)
0.2 (−0.8, 0.1)
10+
23.1
−0.5 (−1.3, 0.3)
0.1 (−0.8, 0.9)
0.2 (−0.7, 0.1)
Block design
0
24.3
Reference
Reference
Reference
1–9
23.9
−0.4 −1.7, 0.8
−0.2 (−1.4, 1.0)
0.0 −1.4, 1.4
10+
23.4
−0.9 −2.3, 0.5
−0.2 (−1.5, 1.1)
0.1 −1.5, 1.5
Geometric design
0
37.7
Reference
Reference
Reference
1–9
35.8
−1.9 −3.8, −0.1
−1.6 −3.3, 0.0
−2.0 −3.8, −0.1
10+
35.1
−2.6 −4.7, −0.5
−1.9 −4.0, 0.1
−2.0 −4.3, 0.2
aWPPSI-R Wechsler Preschool and Primary Scale of Intelligence-Revised.
bParental education, maternal IQ, maternal prenatal alcohol consumption, the child’s sex, age at testing, and tester.
cParental education, maternal IQ, prenatal maternal alcohol consumption, the child’s sex, age at testing, and tester, maternal age, parity, maternal marital status, prenatal paternal smoking, postnatal parental smoking, breast feeding, maternal prepregnancy BMI, the child’s sex, age at testing, health status, family/home environment.
