Maternal Exposure to Ambient Air Pollution and Risk of Preeclampsia: A Population-Based Cohort Study in Scania, Sweden

Abstract

The aim of this study was to investigate the risk of developing preeclampsia (PE) associated with gestational exposure to ambient air pollutants in southern Sweden, a low-exposure area. We used a cohort of 43,688 singleton pregnancies and monthly mean exposure levels of black carbon (BC), local and total particulate matter (PM 2.5 and PM 10 ), and NO X at the maternal residential address estimated by Gaussian dispersion modeling from 2000 to 2009. Analyses were conducted using binary logistic regression. A subtype analysis for small-for-gestational age (SGA) was performed. All analyses were adjusted for obstetrical risk factors and socioeconomic predictors. There were 1286 (2.9%) PE cases in the analysis. An adjusted odds ratio (AOR) of 1.35 with a 95% confidence interval (CI) of 1.11-1.63 was found when comparing the lowest quartile of BC exposure to the highest quartile in the third trimester The AOR for PE associated with each 5 µg/m 3 increase in locally emitted PM 2.5 was 2.74 (95% CI: 1.68, 4.47) in the entire pregnancy. Similar patterns were observed for each 5 µg/m 3 increment in locally emitted PM 10 . In pregnancies complicated by PE with SGA, the corresponding AOR for linear increases in BC was 3.48 (95% CI: 1.67, 7.27). In this low-level setting, maternal exposure to ambient air pollution during gestation was associated with the risk of developing PE. The associations seemed more pronounced in pregnancies with SGA complications, a finding that should be investigated further.

The impact of particulate matter 2.5 on the risk of preeclampsia: an updated systematic review and meta-analysis

“…Assibey-Mensah et al ( 2020 ), Dadvand et al ( 2013 ), Dadvand et al ( 2014 ), Lee et al ( 2013 ), Mandakh et al ( 2020 ), Rudra et al ( 2011 ), and Wu et al ( 2009 ) observed that PM2.5 exposure was positively correlated with preeclampsia. Choe et al ( 2018 ) and Savitz et al ( 2015 ) indicated nonsignificant or infinitesimal association between PM2.5 and preeclampsia.…”

“…Of the remaining 12 studies, 1 study was excluded because it did not describe the effect of PM2.5 on preeclampsia but rather the components of PM2.5, 1 study was excluded because it was a secondary analysis of a previous study, and 1 of 2 studies was excluded because it was conducted on the same population at different times. Finally, 9 studies ultimately met the selection criteria (Assibey-Mensah et al 2020 ; Choe et al 2018 ; Dadvand et al 2013 , 2014 ; Lee et al 2013 ; Mandakh et al 2020 ; Rudra et al 2011 ; Savitz et al 2015 ; Wu et al 2009 ).

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“…In addition to focusing on the correlation between PM2.5 exposure and the entire gestation period, some studies also divided the entire gestational period into three trimesters or nine gestational months to examine the association between PM2.5 exposure at different gestational stages and the risk of preeclampsia (Assibey-Mensah et al 2020 ; Choe et al 2018 ; Dadvand et al 2013 ; Lee et al 2013 ; Rudra et al 2011 ; Savitz et al 2015 ). Moreover, some studies further divided preeclampsia according to severity (Savitz et al 2015 ), early-onset versus late-onset (Assibey-Mensah et al 2020 ; Dadvand et al 2013 ; Mandakh et al 2020 ), or preeclampsia with versus without small-for-gestational age fetus (Mandakh et al 2020 ).…”

“…Previous studies have shown that maternal PM2.5 exposure increases the risk of preeclampsia (Assibey-Mensah et al 2020;Dadvand et al 2013Dadvand et al , 2014Lee et al 2013;Mandakh et al 2020;Rudra et al 2011;Wu et al 2009), but other studies have challenged this positive correlation (Choe et al 2018;Savitz et al 2015). Of the 9 selected studies designed to assess a possible relationship between PM2.5 exposure during pregnancy and the risk of developing preeclampsia, 7 studies revealed a positive association.…”

“…Some studies have reported that atmospheric PM2.5 can enter the blood circulation and reach the maternal placenta causing or aggravating oxidative stress and inflammation, resulting in placental dysfunction and even preeclampsia (Brunst et al 2018 ; Dadvand et al 2013 ; Li et al 2019 ; Slama et al 2008 ). There is increasing evidence that PM2.5 exposure during pregnancy is positively associated with the risk of preeclampsia (Assibey-Mensah et al 2020 ; Dadvand et al 2013 , 2014 ; Lee et al 2013 ; Mandakh et al 2020 ; Rudra et al 2011 ; Wu et al 2009 ); some studies have even suggested that PM2.5 exposure during a particular gestational period can increase the risk of preeclampsia (Lee et al 2013 ; Mandakh et al 2020 ). A systematic review and meta-analysis published 6 years ago assessed the correlation between PM2.5 exposure during pregnancy and preeclampsia but was limited by the small number of studies included and the lack of subgroup analysis for effect modification of this association (Pedersen et al 2014 ).…”