Longitudinal Associations between Ambient Air Pollution and Angiogenic Biomarkers among Pregnant Women in the LIFECODES Study, 2006–2008

Abstract

Background: Exposures to ambient air pollution during pregnancy have been linked to adverse pregnancy outcomes such as preeclampsia and fetal growth restriction. Although evidence has shown that women with preeclampsia have higher ratio of soluble fms-like tyrosine kinase 1 to placental growth factor (sFlt-1/PlGF ratio), the potential impact of air pollution on markers of placental growth and function has not been well studied. Objectives: We aimed to examine longitudinal associations between ambient air pollution exposure and angiogenic factors among pregnant women in LIFECODES, a prospective birth cohort and biorepository in Massachusetts in the United States. Methods: PlGF and sFlt-1 were measured among pregnant women using plasma samples collected around 10, 18, 26, and 35 wk’ gestation. Women’s exposures to ozone ( ), fine particulate matter with aerodynamic diameter ( ), and nitrogen dioxide ( ) within 1, 2, 4, and 8 wk prior to each plasma sample collection were estimated based on geocoded residential addresses, and mixed effect linear regression models were fitted to assess their associations with sFlt-1/PlGF ratio, sFlt-1 (ng/mL), and PlGF (pg/mL). Percent changes in outcomes associated with each interquartile range increase in exposures were reported, along with their 95% confidence intervals. Results: A total of 1,066 pregnant women were included. In the multipollutant models, significant associations were observed for increased sFlt-1/PlGF ratio ( 3–8 wk’ gestation, : 35–39 wk’ gestation), elevated sFlt-1 ( : 26–34 wk’ gestation, : 3–8 wk’ gestation), decreased sFlt-1 ( : 4–8 wk’ gestation), and decreased PlGF ( : 34–39 wk’ gestation) after adjusting for sociodemographic status, smoking, drinking, body mass index, parity, history of chronic hypertension, and conception time. Discussion: Exposures to during early pregnancy and exposures to and during late pregnancy were associated with increased sFlt-1/PlGF ratio, elevated sFlt-1 and with decreased PlGF, which may be a potential mechanism underlying ambient air pollution’s impacts on adverse pregnancy and birth outcomes. https://doi.org/10.1289/EHP11909

Invited Perspective: Opportunities and Obstacles of Longitudinal Data in Pregnancy to Quantify Mechanisms and Understand Etiology

“… 1 The paper by Zheng et al. 2 in this issue of Environmental Health Perspectives helps to fill this gap by characterizing the longitudinal associations of exposure to ozone, , and with angiogenic biomarkers hypothesized to be associated with preeclampsia. This type of study can improve our understanding of how and why exposure to air pollutants matters for pregnant people and why exposure during certain critical windows can be more predictive of adverse outcomes in comparison with relying on estimates of average exposure levels across the entire prenatal period.…”