Infant neurobehavioural consequences of prenatal cigarette exposure: A systematic review and meta‐analysis

Prenatal exposure to cigarettes leads to alterations in brain development during pregnancy. This has an impact on postnatal psychological and behavioural processes, affecting an infant's neurobehavioural profile with little known about which aspects are affected. The evidence was synthesized to assess the effects of prenatal cigarette smoke exposure on neurobehavioural outcomes within the first year of life. Methods: Six databases were searched (Web of science core collections, MEDLINE, Psychinfo, CINAHL, EBSCOhost ebook collection, Opengrey) in November 2018. Eligible studies (n=17) had to include a measure of prenatal cigarette exposure and a neurobehavioural assessment ≤1 year of age. Results: In the first year of life specific areas of neurobehavioural functioning are related to prenatal cigarette exposure with eight out of 10 areas of neurobehaviour having significant medium (negative affect, attention, excitability, irritability and orientation) or small (muscle tone, regulation and difficult temperament) pooled effect sizes. Only lethargy and stress did not show any significant pooled effects. Conclusion: Prenatal cigarette exposure affects a significant range of behaviours during the first year of life.