Few studies investigated the association between maternal smoking during pregnancy and offspring suicide risk, none considering postnatal smoking exposure. We investigated associations between maternal smoking patterns during the pre- and postnatal periods and adolescent suicidal ideation and attempt.
We identified longitudinal patterns of maternal smoking from the prenatal period to the end of childhood (children’s age 12 years, 10 assessments) among participants in the Québec Longitudinal Study of Child Development (N = 1623). We estimated associations between maternal smoking patterns and offspring self-reported suicidal ideation and attempt (ages 13-20). Background confounding factors (e.g., socioeconomic, familial, mental health) were controlled using propensity score inverse-probability weighting (IPW).
Participants reporting suicidal ideation and attempt were 9.3% and 8.4%, respectively. We identified four maternal smoking patterns: non-smoking (66.5%), increasing (5.5%), decreasing (9.3%), persistent (18.5%). Children exposed to persistent (OR=2.92, CI=1.99-4.30) and increasing (OR=2.06, CI=1.13-3.74) maternal smoking were more likely to attempt suicide, compared to non-exposed children. Accounting for confounding factors using IPW fully explained the association between increasing smoking and suicide attempt (OR=0.95, CI=0.39-2.09) but only reduced the association between persistent exposure and suicide attempt (OR=2.30, CI=1.04-4.99). No increased suicide attempt risk was found for children of mothers with a decreased smoking pattern. We found no associations for suicidal ideation.
Propensity score cannot account for unmeasured confounding factors; attrition limits generalizability.
Offspring of mothers who smoked persistently and heavily prenatally and postnatally were at increased risk of suicide attempt in adolescence. Future studies should elucidate biological and psychosocial mechanisms potentially at play in these associations.

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