Prenatal exposure to secondhand smoke may increase the risk of postpartum depressive symptoms.

Background: The harmful effects of smoking during pregnancy on occurrence of postpartum depressive symptoms (PPDS) have been well studied, but there is little research on the association of secondhand smoke (SHS) exposure during pregnancy with PPDS. This study aimed to explore the relationship between prenatal exposure to SHS during pregnancy and PPDS.

Methods: The authors analyzed data from 6884 women who participated in the North Carolina Pregnancy Risk Assessment and Monitoring System survey (2004-08). Data on the exposure (prenatal SHS), outcome (PPDS) and covariates were obtained from self-reported questionnaires. Univariable and multivariable logistic regression was used for data analysis.

Results: The prevalence of PPDS was 16.5%. In the unadjusted analysis, women exposed to SHS during pregnancy had nearly twice the odds of PPDS than the unexposed (odds ratio, OR = 1.90, 95% confidence interval, CI: 1.61-2.26). After adjusting for potential confounders, the association between SHS and PPDS was weakened but remained statistically significant (OR = 1.49, 95% CI: 1.23-1.80). A dose-response relationship was not evident in the analyses. Maternal smoking during pregnancy did not appear to modify the association between SHS and PPDS.

Conclusions: The current study identified a positive association between SHS and PPDS.