ABSTRACT
The association between oxidative protein damage in early pregnant women and ambient fine particulate matter (PM2.5) is unknown. We estimated the effect of PM2.5 exposures within seven days before blood collection on serum 3-nitrotyrosine (3-NT) and advanced oxidation protein products (AOPP) in 100 women with normal early pregnancy (NEP) and 100 women with clinically recognized early pregnancy loss (CREPL). Temporally-adjusted land use regression model was applied for estimation of maternal daily PM2.5 exposure. Single-day lag effect of PM2.5 was analyzed using multivariable linear regression model. Net cumulative effect and distributed lag effect of PM2.5 within seven days were analyzed using distributed lag non-linear model. In all 200 subjects, the serum 3-NT were significantly increased with the single-day lag effects (4.72%–8.04% increased at lag 0–2), distributed lag effects (2.32%–3.49% increased at lag 0–2), and cumulative effect within seven days (16.91% increased). The single-day lag effects (7.41%–10.48% increased at lag 0–1), distributed lag effects (3.42%–5.52% increased at lag 0–2), and cumulative effect within seven days (24.51% increased) of PM2.5 significantly increased serum 3-NT in CREPL group but not in NEP group. The distributed lag effects (2.62%–4.54% increased at lag 0–2) and cumulative effect within seven days (20.25% increased) of PM2.5 significantly increased serum AOPP in early pregnant women before the coronavirus disease (COVID-19) pandemic but not after that. In conclusion, PM2.5 exposures were associated with oxidative stress to protein in pregnant women in the first trimester. Wearing masks may be potentially preventive in PM2.5 exposure and its related oxidative protein damage. Whether PM2.5–associated systemic 3-NT increase contributes to the pathogenic mechanisms of spontaneous abortion remains to be further investigated.