Effects of maternal cigarette smoking during pregnancy on cognitive parameters of children and young adults: A literature review

The long term effects of maternal smoking during pregnancy on the cognitive development of the child are not well understood due to conflicting findings in past research. The aim of this paper was to provide an up to date, critical review of the literature to determine whether there is evidence of a relationship between tobacco smoke exposure in utero and cognitive functioning. We systematically reviewed observational studies (dated 2000–2011) that examined associations between tobacco smoke exposure in utero due to maternal smoking and performance on cognitive, intelligence, neurodevelopmental and academic tests. Eligible studies were identified through searches of Web of Knowledge, Medline, Science Direct, Google Scholar, CINAHL, EMBASE, Zetoc and Clinicaltrials.gov databases. The review found evidence of a relationship between tobacco smoke exposure in utero and reduced academic achievement and cognitive abilities independent of other variables. Maternal smoking during pregnancy may therefore be a modifiable risk factor for reduced cognitive abilities later in the life of the child. Giving up smoking during pregnancy should be initiated as early as possible to reduce the impact on the child's cognitive development.

► We examined the effect of prenatal tobacco smoke exposure on cognitive outcomes.
► We systematically reviewed recent articles to evaluate the proposed relationship.
► Evidence suggests small but significant associations between the two variables.
► The associations last into adulthood and are independent of maternal factors.
► Postnatal factors must be controlled to determine the strength of the association.