Ferguson Kelly K, Chin Helen B
Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina.
Curr Epidemiol Rep. 2017 Mar;4(1):56-71. doi: 10.1007/s40471-017-0099-7. Epub 2017 Jan 27.
Preterm birth is a significant worldwide health problem of uncertain origins. The extant body of literature examining environmental contaminant exposures in relation to preterm birth is extensive but results remain ambiguous for most organic pollutants, metals and metalloids, and air pollutants. In the present review we examine recent epidemiologic studies investigating these associations, and identify recent advances and the state of the science. Additionally, we highlight biological mechanisms of action in the pathway between chemical exposures and preterm birth, including inflammation, oxidative stress, and endocrine disruption, that deserve more attention in this context.
Important advances have been made in the study of the environment and preterm birth, particularly in regard to exposure assessment methods, exploration of effect modification by co-morbidities and exposures, and in identification of windows of vulnerability during gestation. There is strong evidence for an association between maternal exposure to some persistent pesticides, lead, and fine particulate matter, but data on other contaminants is sparse and only suggestive trends can be noted with the current data.
Beyond replicating current findings, further work must be done to improve understanding of mechanisms underlying the associations observed between environmental chemical exposures and preterm birth. By examining windows of vulnerability, disaggregating preterm birth by phenotypes, and measuring biomarkers of mechanistic pathways in these epidemiologic studies we can improve our ability to detect associations with exposure, provide additional evidence for causality in an observational setting, and identify opportunities for intervention.
早产是一个全球范围内起源不明的重大健康问题。现有大量文献研究环境污染物暴露与早产的关系，但对于大多数有机污染物、金属和类金属以及空气污染物而言，结果仍不明确。在本综述中，我们考察了近期调查这些关联的流行病学研究，确定了最新进展和科学现状。此外，我们强调了化学暴露与早产之间途径中的生物学作用机制，包括炎症、氧化应激和内分泌干扰，在这方面值得更多关注。
在环境与早产的研究方面取得了重要进展，特别是在暴露评估方法、合并症和暴露对效应修饰的探索以及妊娠期脆弱窗口的识别方面。有强有力的证据表明母亲接触某些持久性农药、铅和细颗粒物与早产之间存在关联，但关于其他污染物的数据稀少，根据目前的数据只能看出一些暗示性趋势。
除了重复当前的研究结果外，还必须进一步开展工作，以增进对环境化学暴露与早产之间观察到的关联背后机制的理解。通过在这些流行病学研究中考察脆弱窗口、按表型对早产进行分类以及测量作用机制途径的生物标志物，我们可以提高检测与暴露关联的能力，在观察性研究中为因果关系提供更多证据，并确定干预机会。
