Passive smoking and behavioural problems in children: Results from the LISAplus prospective birth cohort study.

OBJECTIVE: To analyse the association between pre- and postnatal exposure to tobacco smoke and child behavioural problems and to further investigate the influence of trimester-specific exposure to maternal smoking and the impact of paternal smoking at home on the same outcome. METHODS: Data of 3097 German children recruited at birth for a population-based, prospective study were used. Detailed information on children's tobacco smoke exposure was collected by self-administered questionnaires at each follow-up. Behavioural outcomes were measured by the Strengths and Difficulties Questionnaire applied at 10-year follow-up. RESULTS: Children exposed to environmental tobacco smoke at home showed increased risks of hyperactivity/inattention problems. Only smoking during the entire pregnancy increased the risk for conduct and hyperactivity/inattention problems (proportional odds ratio (pOR)=1.58, 95% confidence interval (CI)=1.06-2.37 and pOR=1.67, CI=1.03-2.72). Pre- and postnatal exposure to paternal smoking was associated with hyperactivity/inattention problems in children of non-smoking mothers (pOR=1.97, CI=1.06-3.65). Effect estimates were adjusted for study centre, sex, parental educational level, mother's age at birth, having a single parent and time spent in front of a screen. CONCLUSIONS: Not only maternal smoking during pregnancy but also paternal smoking at home should be considered as a risk for hyperactivity/inattention problems in children