Association Between Maternal Smoking During Pregnancy and Severe Mental Illness in Offspring

Abstract

Maternal smoking during pregnancy (SDP) is associated with a breadth of adverse offspring outcomes, including pregnancy-related, neurodevelopmental, and behavioral problems.^1-3 In particular, recent studies have provided novel evidence of associations between SDP and offspring bipolar disorder,⁴ schizophrenia,⁵ and related outcomes.⁶ These associations raise the possibility that SDP exposure has causal teratogenic effects on the risk of severe mental illness (SMI).⁷ Because nicotine and carbon monoxide cross the placenta and may directly and indirectly (eg, via hypoxia) affect fetal neurodevelopment,⁸ this hypothesis is biologically plausible. Moreover, 8% of pregnant women in the United States smoke,⁹ meaning that SDP exposure could represent a potentially modifiable and important source of risk for SMI.¹⁰ Recent editorials have made explicit causal claims regarding teratogenic effects of SDP on offspring neurodevelopment and psychopathology.^11,12