Climate Change and Health: Assessing the Risk of Preterm Delivery

描述（由申请人提供）：美国国立卫生研究院（NIH）和国立环境卫生与科学研究所（NIEHS）最近发表了一份白皮书，强调有必要研究气候变化对人类健康的影响，特别是对包括孕妇在内的弱势群体的影响。早产（PTD）是婴儿死亡率和发病率的主要原因，也是我国以及世界其他地区面临的最大公共卫生挑战之一。然而，其病因在很大程度上仍然未知。对空气污染和季节性趋势的研究支持了不良出生结果之间的关系，例如PTD，因此支持需要更多的研究来阐明这种关系。孕妇在热暴露期间可能会增加PTD的风险，因为她们更容易脱水，这可能导致子宫血流量减少，垂体分泌抗利尿激素和催产素以诱导分娩。提出的研究考察了一个创新的假设和一个以前未知的PTD风险因素，这是最近从文献中出现的。具体来说，拟议研究的目的是检查气候变化对PTD风险的影响，这将是第一批旨在解决临床环境中这种关联的研究之一。为了实现提出的目标，我们将利用Kaiser Permanente Northern California （KPNC）的成员进行一项病例交叉研究，KPNC是一个综合医疗保健服务系统，每年有超过33,000例分娩。病例交叉法是一种特别适合于研究短期高环境温度与PTD风险之间关系的研究设计，因为它具有消除研究设计固有的潜在测量和未测量混杂因素的优势。拟议的研究将使用kpnc电子病历（EMR）中1995年1月至2009年12月期间分娩的数据，其中包括分娩时的居住信息。加州灌溉和管理系统和美国环境保护署将提供产妇住宅表观温度的数据，即温度和相对湿度的综合测量。将通过KPNC的电子病历确定约50万新生儿队列，其中约10%的新生儿预计为早产。分析将根据季节、母亲种族/民族、母亲年龄和社会经济地位进行分层。这项研究的发现将有助于对这种关系的初步理解。一旦确定了PTD风险增加与体表温度之间的关系，就可以实施公共卫生干预措施，以减少热暴露增加对孕妇的影响，同时针对风险最大的孕妇。预防措施可能包括多喝水和补充电解质，待在室内有空调的环境中，在温暖的季节，尤其是热浪来的时候，与他人待在一起。

DESCRIPTION (provided by applicant): The National Institutes of Health (NIH) and National Institute of Environmental Health and Science (NIEHS) have recently published a White Paper emphasizing the need to study the impact of climate change on human health, specifically among vulnerable populations including pregnant women. Pre-term delivery (PTD) is the leading cause of infant mortality and morbidity and among the top public health challenges facing our nation as well as the rest of the world. Yet the etiology remains largely unknown. Studies of air pollution and seasonal trends have supported a relationship between adverse birth outcomes, such as PTD, thus supporting the need for more research to elucidate this relationship. Pregnant women may be at increased risk of PTD during periods of heat exposure, since they are more likely to be dehydrated, which could result in decreased uterine blood flow and increased pituitary secretion of anti-diuretic hormone and oxytocin to induce labor. The proposed study examines an innovative hypothesis and a previously unknown risk factor for PTD that has newly emerged from the literature. Specifically, the objective of the proposed study is to examine the impact of climate change on the risk of PTD, and will be among the first such studies designed to address this association in a clinical setting. To achieve the proposed aims, we will conduct a case-crossover study utilizing members of Kaiser Permanente Northern California (KPNC), an integrated health care delivery system with more than 33,000 deliveries each year. The case-crossover is a study design uniquely suited for examining the association between short-term high ambient temperature and the risk of PTD, as it has the advantage of eliminating potential measured and unmeasured confounders inherently by study design. The proposed study will use data on deliveries that occurred between January 1995 and December 2009 from KPNCs electronic medical records (EMR), which includes information on residence at the time of deliveries. Data on maternal residential apparent temperature, a measure of both temperature and relative humidity combined, will be provided by the California Irrigation and Management System and the US Environmental Protection Agency. A cohort of approximately half a million births will be identified through KPNC's EMR, and approximately ten percent of these births are expected to be preterm. The analyses will be stratified by season, and also by maternal race/ethnic group, maternal age, and socioeconomic status. Findings from this study will contribute to the nascent understanding of this relationship. Once the relationship between increased risk of PTD and apparent temperature has been established, public health interventions can be implemented to reduce the impact of increasing heat exposure on pregnant women, while targeting those who are at greatest risk. Precautions may include drinking more fluids and electrolytes, staying indoors in air conditioned environments, and being with others during the warm season, especially during heat waves.