Prenatal and postnatal maternal smoking as risk factors for preschool children's mental health

Aim: To identify maternal prenatal and postnatal smoking as risk factors for psychosocial behaviour problems in Swedish preschool children. Methods: This prospective, longitudinal population study compared mothers' self-reported smoking during pregnancy and when the child was 3 mo old with behaviour problems according to Achenbach's Child Behavior Checklist at 3 y ( 1428 children) and 5.5 y of age ( 677 of the children). Results: 16% of the mothers smoked during pregnancy and the same number after the birth of the child. Controlling for possible confounding variables, maternal smoking was significantly related to externalizing problems, aggressive behaviour, and destructive/delinquent behaviour both at 3 y and 5.5 y. The effect was as strong for girls as for boys. Length and weight were lower for children of smoking mothers than for children of non-smoking mothers. Conclusion: Our study supports the importance of preventing maternal smoking during pregnancy and the infant years. Even a few cigarettes per day have negative consequences for the child. The goal must be total abstinence from smoking both pre- and postnatally.