Abstract：
The relationship between maternal peripheral blood mitochondrial DNA and adverse pregnancy outcomes, specifically preterm birth (PTB), remains uncertain. To investigate the effects of preconception mitochondrial DNA copy number (mtDNAcn) on the association between prenatal air pollutants exposure and PTB risk, a total of 1871 expectant mothers from six regions in Henan Province were recruited. Information regarding air pollutants was obtained from 151 environmental monitoring sites, and relative mtDNAcn was evaluated using real-time PCR analysis. After adjusting for potential confounding variables, it was determined that the risk of PTB increased with elevated levels of inhalable particulate matter (PM10), fine particulate matter (PM2.5), sulfur dioxide (SO2), carbon monoxide (CO) and ozone (O3) exposure (P < 0.05) but decreased with higher nitrogen dioxide (NO2) exposure (0.05 < P < 0.10) during the entire pregnancy. Additionally, the preconception relative mtDNAcn was lower in the PTB group (0.82 ± 0.23) compared to the term group (0.92 ± 0.29). Furthermore, for each 0.1-unit increase in preconception mtDNAcn, the risk of PTB decreased by 14.8%. Stratified analyses revealed that the risk of PTB rose with increasing O3 concentrations, regardless of the relative mtDNAcn. Moreover, the study found a significant association between PTB risk and prenatal exposure to elevated PM10, PM2.5, SO2, and CO, particularly in mothers with low mtDNAcn (≤0.88) (P < 0.05). Conversely, a decrease in the PTB risk was observed with elevated NO2 exposure in mothers with high mtDNAcn (>0.88). Interaction analysis revealed that exposure to PM10, PM2.5, SO2, NO2, and CO interacted with mtDNAcn, respectively, affecting PTB risk (P-interaction<0.05). These findings indicate a noteworthy association between PTB risk and prenatal air pollutants exposure, which is influenced by the preconception mtDNAcn.
摘要：
孕妇外周血线粒体DNA与不良妊娠结局的关系,特别是早产（PTB），仍然不确定。探讨孕前线粒体DNA拷贝数（mtDNAcn）对产前空气污染物暴露与PTB风险之间关系的影响。共招募了来自河南省六个地区的1871名准妈妈。有关空气污染物的信息是从151个环境监测地点获得的，使用实时PCR分析评估相对mtDNAcn。在调整潜在的混杂变量后，确定PTB的风险随着可吸入颗粒物（PM10）水平的升高而增加，细颗粒物（PM2.5），二氧化硫(SO2),在整个怀孕期间，一氧化碳（CO）和臭氧（O3）暴露（P<0.05），但随着二氧化氮（NO2）暴露的增加而降低（0.050.88)的母亲中,NO2暴露量升高时,观察到PTB风险降低.相互作用分析表明，暴露于PM10，PM2.5，SO2，NO2和CO与mtDNAcn相互作用，分别,影响PTB风险（P交互作用<0.05）。这些发现表明，PTB风险与产前空气污染物暴露之间存在值得注意的关联，受到前概念mtDNAcn的影响。
