Exposure to chemical components of fine particulate matter and ozone, and placenta-mediated pregnancy complications in Tokyo: a register-based study

Abstract

Background Maternal exposure to fine particulate matter (PM2.5) was associated with pregnancy complications. However, we still lack comprehensive evidence regarding which specific chemical components of PM2.5 are more harmful for maternal and foetal health. Objective We focused on exposure over the first trimester (0–13 weeks of gestation), which includes the early placentation period, and investigated whether PM2.5 and its components were associated with placenta-mediated pregnancy complications (combined outcome of small for gestational age, preeclampsia, placental abruption, and stillbirth). Methods From 2013 to 2015, we obtained information, from the Japan Perinatal Registry Network database, on 83,454 women who delivered singleton infants within 23 Tokyo wards (≈627 km2). Using daily filter sampling of PM2.5 at one monitoring location, we analysed carbon and ion components, and assigned the first trimester average of the respective pollutant concentrations to each woman. Results The ORs of placenta-mediated pregnancy complications were 1.14 (95% CI = 1.08–1.22) per 0.51 μg/m3 (interquartile range) increase of organic carbon and 1.11 (1.03–1.18) per 0.06 μg/m3 increase of sodium. Organic carbon was also associated with four individual complications. There was no association between ozone and outcome. Significance There were specific components of PM2.5 that have adverse effects on maternal and foetal health.

Prenatal Exposure to PM2.5 and Its Specific Components and Risk of Hypertensive Disorders in Pregnancy: A Nationwide Cohort Study in China

“…Significant associations were also found between increased the risk of pre-eclampsia and the second trimester exposure of BC in a cohort study involving 228,438 births in the United States; 22 however, another cohort study involving 83,454 Japanese women showed that exposure to the carboncontaining components of PM 2.5 in the first trimester was positively associated with placenta-mediated pregnancy complications (such as pre-eclampsia). 38 The second trimester was a sensitive window for BC exposure, possibly because maternal plasma volume increased with the steepest increase occurring during the second trimester, and body load for pregnant women increases. 39 BC is mainly emitted from the incomplete combustion process of biomass and fossil fuels.…”

Ozone Exposure During Pregnancy and Risk of Gestational Hypertension or Preeclampsia in China

“… 16 , 19 , 27 , 35 , 36 The method we used to assess individual O 3 exposure outperformed previous exposure assessment methods in terms of exposure accuracy, which may also account for the differences in the results. 18 , 19 , 35 …”

“… 16 A retrospective case-control study in the US and a registry-based study in Japan showed similar associations between maternal O 3 exposure and HDP risk. 17 , 18 In contrast, some studies from South Korea and China did not show an association of O 3 exposure with HDP risk. 19 , 20 This inconsistency may be due to different populations, different exposure assessment approaches, unadjusted residual confounders, selection bias, or the levels of O 3 pollution across study areas.…”

“…A growing body of literature has found an association between O 3 exposure during pregnancy and HDP risk. 16 , 17 , 18 For instance, a cohort study of 655 529 participants in Florida showed that exposure to O 3 could play a role in increased HDP risk, and early pregnancy appeared to be a potential window of susceptibility for exposure. 16 A retrospective case-control study in the US and a registry-based study in Japan showed similar associations between maternal O 3 exposure and HDP risk.…”

Prenatal exposure to fine particulate matter and the risk of spontaneous preterm birth: A population-based cohort study of twins

“…Identifying critical exposure windows would allow for the design of targeted prevention strategies, as well as the exploration of the potential biological mechanisms underlying the associations of PM 2.5 exposure with PTB. In previous research evaluating the effect of gestational PM 2.5 exposure on pregnancy complications of placental origin, the critical window was identified as the first trimester ( 34 ). In this study, PM 2.5 exposure during the second trimester demonstrated significant associations with PTB, which is consistent with some previous epidemiological studies ( 35 – 37 ), whereas other studies identified the late stage of pregnancy as the most significant critical window ( 19 , 20 , 38 ).…”