Association between prenatal exposure to ambient air pollutants and postpartum depressive symptoms: A multi-city cohort study.

Women are vulnerable to depression during postpartum period. While several studies have shown associations between ambient air pollution exposure and depression in general population, there was few studies focused on the effect of various air pollutants on postpartum depression (PPD). This study is designed to explore the association between prenatal exposure to air pollutants and PPD, and to reveal the potential vulnerable exposure time point. The study enrolled 10,209 pregnant women who delivered between October 2019 and February 2021 in 5 participating hospitals from 3 cities in China. Edinburgh Postnatal Depression Scale (EPDS) was administered at 6 weeks postpartum to identify PPD symptoms. Associations between PPD symptoms and exposure levels in PM 2.5 , PM 10, SO 2 , CO, NO 2 , and O 3 averaged over the whole pregnancy and each trimester were estimated using logistic regression models after adjusting for potential confounding factors. Distributed lag models (DLMs) were used to determine the relevant associations in each gestational week. The risk for developing PPD symptoms was significant following a 10 μg/m3 increase in PM 10 (aOR = 1.47, 95%CI:1.36–1.59), NO 2 (aOR = 1.63, 95%CI:1.44–1.85), and 0.1 mg/m3 increase in CO (aOR = 2.31, 95%CI: 1.99–2.69) during the whole pregnancy. Similar results were also found in exposure during each trimester of pregnancy. Besides, SO 2 exposure during the second trimester was a major risk factor for developing PPD symptoms (aOR = 1.10, 95%CI:1.03–1.18). Consistent effects were also observed in DLMs, except for PM 2.5 and O 3 , which showed no significant sensitive windows throughout pregnancy period. Exposure to PM 10 , CO, NO 2 , and SO 2 in pregnancy is associated with increased risks of developing depression at 6 weeks postpartum. Our findings reveal the importance of air pollution control for preventing maternal mental health disorders among the public. [Display omitted] • Exposure to PM10, NO2 and CO in pregnancy increased risk of developing depression at 6 weeks postpartum. •The second trimester of pregnancy was the most susceptible period for developing PPD when exposed to SO2. •Prenatal exposure to multiple ambient air pollutants may contribute to development of PPD. [ABSTRACT FROM AUTHOR]