Parental smoking during pregnancy and cardiovascular structures and function in childhood: the Generation R Study.

BACKGROUND Foetal smoke exposure might lead to foetal developmental adaptations that permanently affect the cardiovascular system. We assessed the associations of both maternal and paternal smoking during pregnancy with childhood cardiovascular structures and function. METHOD In a prospective cohort study among 5565 children, we examined whether maternal and paternal smoking during pregnancy are associated with blood pressure, carotid-femoral pulse wave velocity and left cardiac structures and function in 6-year-old children. RESULTS As compared with children from non-smoking mothers, children from mothers who smoked more than 10 cigarettes per day had a higher diastolic blood pressure [difference 1.43 mmHg (95% confidence interval: 0.22, 2.63)]. Maternal smoking during pregnancy was not associated with systolic blood pressure, childhood carotid-femoral pulse wave velocity or left cardiac structures. Maternal smoking of 10 or more cigarettes per day was associated with a higher fractional shortening in childhood [difference 1.01% (95% confidence interval: 0.18, 1.84)]. Among mothers who did not smoke during pregnancy, paternal smoking was associated with aortic root diameter but not with other cardiovascular outcomes. CONCLUSIONS Maternal smoking during pregnancy is associated with higher diastolic blood pressure and fractional shortening, although the effect estimates are small. The stronger effect estimates for maternal smoking compared with paternal smoking might suggest that direct intrauterine adaptive responses are involved as underlying mechanisms.