The longitudinal association between second-hand smoke exposure and maternal depression among non-smoking pregnant women in East China: A prospective birth cohort study

Objectives

Second-hand smoke (SHS) exposure during pregnancy is common and may negatively impact maternal mental health. Recent evidence on the association between SHS exposure and depression during pregnancy remains inconsistent. This study aims to examine the longitudinal association between SHS exposure and maternal depression.

Study design

A prospective birth cohort study.

Methods

From October 2017 to September 2021, we conducted a prospective birth cohort study including 5311 pregnant women. We applied mixed-effects models and group-based multivariate trajectory modeling to estimate the longitudinal association between SHS exposure and depression during pregnancy.

Results

The prevalence of depression during pregnancy was 40.61 %, 19.00 %, and 20.35 % in the first, second, and third trimesters, respectively; 50.52 % of the women were exposed to SHS during pregnancy. Compared to unexposed women, those with SHS exposure had higher odds of depression in the first (OR: 1.34, 95 % CI: 1.19–1.51), second (OR: 1.70, 95 % CI: 1.45–1.98), and third trimesters (OR: 1.71, 95 % CI: 1.47–1.99). Exposure in one, two, or three trimesters showed progressively stronger associations (ORs: 1.37, 1.89, 2.08, respectively). SHS exposure was associated with an increased trajectory of depression (OR: 1.38, 95 % CI: 1.05–1.81). The association between SHS and depression was more pronounced among unemployed mothers who had good sleep quality during pregnancy.

Conclusions

Exposure to SHS during pregnancy affects current and subsequent depression. Addressing SHS exposure is essential to promote mental health and improve the health outcomes of mothers and offspring.