Journal of Pregnancy / 2012 / Article / Tab 2

Research Article

Effects of Tobacco Smoking in Pregnancy on Offspring Intelligence at the Age of 5

Table 2

Maternal smoking in pregnancy and WPPSI-Ra performance.

Average number of cigarettes/dayCrudeAdjusted for core confoundersbAdjusted for potential confoundersc
Mean scoreMean difference (95% CI)Mean difference (95% CI)Mean difference (95% CI)

Full-scale IQ
 0106.1ReferenceReferenceReference
 1–9103.3−2.8 (−5.5, −0.1)−1.0 (−3.4, 1.4) −0.9 (−3.6, 1.8)
 10+102.5−3.6 (−6.1, −1.2)−1.0 (−3.3, 1.4)−0.3 (−3.1, 2.5)
Verbal IQ
 0105.3ReferenceReferenceReference
 1–9103.2−2.1 (−4.4, 0.2)−0.5 (−2.6, 1.6)−0.6 (−2.8, 1.7)
 10+102.8−2.5 (−4.7, −0.4)−0.1 (−2.2, 2.0)0.2 (−2.1, 2.8)
Performance IQ
 0105.6ReferenceReferenceReference
 1–9102.6−3.0 (−6.4, 0.5)−1.4 (−4.5, 1.7)−1.0 (−4.7, 2.7)
 10+101.5−4.1 (−7.1, −0.9)−1.7 (−4.6, 1.2)−1.0 (−4.6, 2.6)

aWechsler Preschool and Primary Scale of Intelligence-Revised.
bParental education, maternal IQ, prenatal maternal 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.