The Combined Effects of Fine Particulate Matter and Temperature on Preterm Birth in Seoul, 2010–2016

Abstract

Background: Preterm birth contributes to the morbidity and mortality of newborns and infants. Recent studies have shown that maternal exposure to particulate matter and extreme temperatures results in immune dysfunction, which can induce preterm birth. This study aimed to evaluate the association between fine particulate matter (PM2.5) exposure, temperature, and preterm birth in Seoul, Republic of Korea. Methods: We used 2010–2016 birth data from Seoul, obtained from the Korea National Statistical Office Microdata. PM2.5 concentration data from Seoul were generated through the Community Multiscale Air Quality (CMAQ) model. Seoul temperature data were collected from the Korea Meteorological Administration (KMA). The exposure period of PM2.5 and temperature were divided into the first (TR1), second (TR2), and third (TR3) trimesters of pregnancy. The mean PM2.5 concentration was used in units of ×10 µg/m3 and the mean temperature was divided into four categories based on quartiles. Logistic regression analyses were performed to evaluate the association between PM2.5 exposure and preterm birth, as well as the combined effects of PM2.5 exposure and temperature on preterm birth. Result: In a model that includes three trimesters of PM2.5 and temperature data as exposures, which assumes an interaction between PM2.5 and temperature in each trimester, the risk of preterm birth was positively associated with TR1 PM2.5 exposure among pregnant women exposed to relatively low mean temperatures (<3.4 °C) during TR1 (OR 1.134, 95% CI 1.061–1.213, p < 0.001). Conclusions: When we assumed the interaction between PM2.5 exposure and temperature exposure, PM2.5 exposure during TR1 increased the risk of preterm birth among pregnant women exposed to low temperatures during TR1. Pregnant women should be aware of the risk associated with combined exposure to particulate matter and low temperatures during TR1 to prevent preterm birth.

Climate change, women’s health, and the role of obstetricians and gynecologists in leadership

“…Similar risk was also found for a subpopulation with low average ambient temperature (≤−0.59°C) in the third trimester, 60 highlighting that both extremes of temperature may be cause for concern. Several other studies conducted in Asia have corroborated this newly identified potential for synergistic risk 61,62 …”

“…Several other studies conducted in Asia have corroborated this newly identified potential for synergistic risk. 61 , 62 …”

Association between maximum temperature and PM2.5 with pregnancy outcomes in Lima, Peru

“…Several studies have reported that exposure to high-temperature changes increases the risk of premature birth. 26 , 38 Heat stress could activate the fetal hypothalamic-pituitary-adrenal axis, prompting the placental release of estriol, prostaglandins which could induce labor onset. 38 …”

“…However, exposure to combined effects of temperature and air pollutants on birth outcomes has been scarcely studied. 26 , 27 Wang et al 27 evaluated heatwaves on PTB and reported synergistic effects of PM 2.5 and heat waves, with more PTB with a combination of high PM 2.5 and heatwaves in the week before birth. Kwag et al, 26 in contrast, found that PM 2.5 exposure during the first trimester (TR1) increased the risk of preterm birth among pregnant women exposed to low temperatures during TR1.…”

Association between Maternal Exposure to Ambient Air Pollution and the Risk of Preterm Birth: A Birth Cohort Study in Chongqing, China, 2015–2020

“…Still, thus far, the results of studies on the effects of maternal exposure during pregnancy have been inconsistent. The sensitive window of exposure and the influence level of air pollutants have varied greatly [ 6 , 7 , 8 ]. Further, some of the studies are ecological in nature or limited by a small sample size [ 9 ].…”