Environment/Climate Change
Urinary polycyclic aromatic hydrocarbon metabolites and their association with oxidative stress among pregnant women in Los Angeles Qi Meng* Qi Meng
Introduction Polycyclic aromatic hydrocarbons (PAHs) have been linked to adverse birth outcomes, but few epidemiological studies to date have evaluated associations between urinary PAH metabolites and oxidative stress biomarkers in pregnancy.
Methods We measured a total of 7 PAH metabolites and 2 oxidative stress biomarkers (malondialdehyde (MDA), 8-hydroxy-2’-deoxyguanosine (8-OHdG)) in urine samples collected up to three times during pregnancy in 159 women enrolled at antenatal clinics at the University of California Los Angeles during 2016-2019. Using multiple linear regression models, we estimated the percentage change (%) and 95% confidence interval (CI) in 8-OHdG and MDA measured at each sample collection time per doubling of PAH metabolite concentrations.
Results Most PAH metabolites were positively associated with both urinary oxidative stress biomarkers, MDA and 8-OHdG, but the associations were stronger in early and late pregnancy. Women pregnant with boys exhibited larger increases in both MDA and 8-OHdG in association with PAH exposures in early pregnancy, while for pregnancies of girls we found stronger associations between PAH exposures and MDA in mid-pregnancy.
Conclusion Urinary OH-PAH biomarkers are associated with increases in oxidative stress during pregnancy, especially in early and late pregnancy. Sex differences in associations between PAH exposures and oxidative stress in the future need to be further explored.