To investigate the association between child, and in particular foetal, exposure to tobacco smoke in the family setting and vascular damage in early adulthood.

A cohort study amongst young people born between 1970 and 1973 in the Utrecht region of the Netherlands.

In 1999 and 2000, the intima media thickness (IMT) of the common carotid artery (CCA) of 732 participants with registered birth details was measured by ultrasound. Data on parental smoking were obtained with standardized questionnaires.

The IMT of children born to mothers who smoked during pregnancy (29%) was 13.4 μm thicker than that of children whose mothers did not smoke during pregnancy (95% CI: 5.5-21.3). This difference represents 2.7% of the arterial wall thickness. This could not be explained by age, gender, BMI, pulse pressure or LDL-cholesterol (difference after correction: 9.4 μm; 95% CI: 1.9-16.3), nor by current parental smoking (10.6 μm; 95% CI: 0.4-20.8), current participant smoking and pack-years (11.5 μm; 95% CI: 3.5-19.4) or parental socioeconomic status (13.0 μm; 95% CI: 5.0-21.1). Compared with children from non-smokers, young people had a greater IMT if only the father smoked during pregnancy, an even greater IMT if only the mother smoked and the greatest IMT if both parents smoked during pregnancy (p linear trend = 0.001). Offspring from mothers who smoked an above-average number of cigarettes during pregnancy had a greater IMT than those whose mothers smoked a below-average number of cigarettes or none at all (p linear trend < 0.0001).

Smoking within the family causes damage to the arterial wall in children. This effect may start during pregnancy.