Prenatal tobacco smoke and postnatal secondhand smoke exposure and child neurodevelopment

PURPOSE: To review the recent scientific literature examining the association of prenatal tobacco and postnatal secondhand smoke exposure and child neurodevelopment. RECENT FINDINGS: Low birth weight and decreased in-utero brain growth are two of multiple potential etiologic pathways proposed as mediating the effects of prenatal tobacco smoke exposure on child neurodevelopment. These negative effects of prenatal exposure have been consistently demonstrated in animal models, and in humans have been found as early as the newborn period. The literature on both prenatal and postnatal exposure is remarkably consistent in showing associations with increased rates of behavior problems, including irritability, oppositional defiant behavior, conduct disorders and attention deficit hyperactivity disorder. A more rudimentary literature also suggests deficits in intelligence quotient. Recent studies have focused on elucidating the complex interaction among tobacco exposure, genetics and environmental factors. Questions still remain about the relative roles of prenatal vs. postnatal exposure and the potential role of genetic and social confounders, limiting the ability to infer a causal nature to these associations at this time. The consistency of findings across studies is, however, highly suggestive of a causal relationship between environmental tobacco exposure and adverse behavioral and cognitive outcomes in children. SUMMARY: Prenatal tobacco and postnatal secondhand smoke exposure is consistently associated with problems in multiple domains of children's neurodevelopment and behavior.