Climate Change and Adverse Birth Outcomes

描述（由申请人提供）：全球变暖将导致更强烈、更频繁、持续时间更长的极端天气事件，这与死亡率增加有关。然而，我们对气候变化对健康的影响，包括其对发病率的影响、多种天气因素的共同影响、极端寒冷天气的影响以及是否存在特别脆弱的亚人群的理解仍然存在重大差距。尽管动物实验和有限的人体研究表明极端天气对出生结果的影响具有生物学上的合理性，但人们对其知之甚少。拟议的研究将通过检查怀孕期间暴露于各种极端天气条件或其共同影响是否与不良出生结果（包括选择性出生缺陷、早产和胎儿生长受限）有关来填补这些空白。为了评估空气污染的适应性和潜在的改变，我们将研究地理差异和空气污染对所测试协会的相互影响。此外，该研究还将评估患有某些慢性疾病的孕妇、服用热敏药物的孕妇、社会经济地位较低的孕妇、吸烟或饮酒的孕妇以及从事户外工作的孕妇是否更容易受到极端天气条件的影响。最后，我们将估算孕妇和具有某些特征的妇女的天气归因风险，预测气候变化的生育结果负担，并绘制脆弱性图。我们将使用国家出生缺陷预防研究（NBDPS），这是美国最大的基于人群的出生缺陷潜在危险因素的病例对照研究。出生缺陷病例包括确诊的、选定的排除遗传原因的重大出生缺陷婴儿（N= 23333），对照组为从每个中心随机抽取的未畸形的活产婴儿（N= 8494）。其他妊娠结局将从NBDPS对照组中选择，如早产（< 37周），包括重度早产（<32周）和中度早产（32-37周），以及胎龄小（低于胎龄出生体重的10%）。以夏季平均温度的第90百分位或冬季温度的第10百分位定义的极端天气指标将按强度、持续时间、频率和时间进行评估。其他指标，包括热浪和寒潮、温度、湿度、气压和风的全部范围，以及使用空间天气分类系统的综合天气指数，亦会进行研究。一个两阶段贝叶斯层次模型将用于首先检查每个地区的关联，然后控制区域特征以获得全国范围的估计。k均值聚类分析和蒙特卡罗方法将分别用于估计天气因素聚类和不确定性。这些发现可能会确定一个被忽视的脆弱群体，从而指导气候干预和适应。多学科研究团队有一个独特的机会，通过NBDPS和其他正在进行的项目使用已经收集和地理编码的数据，这确保了项目的可行性和可持续性。

DESCRIPTION (provided by applicant): Global warming will lead to more intense, frequent, and longer-lasting extreme weather events, that have been associated with increased mortality. However, significant gaps remain in our understanding of the impact of climate change on health, including its impact on morbidity, the joint effects of multiple weather factors, effects o extreme cold weather, and whether there are especially vulnerable subpopulations. Little is known about the effect of extreme weather on birth outcomes in spite of biological plausibility suggested by animal experiments and limited human studies. The proposed study will fill these gaps by examining whether exposures to various extreme weather conditions or their joint effects during pregnancy are associated with adverse birth outcomes, including selected birth defects, preterm birth, and fetal growth restriction. To assess acclimatization and potential modification by air pollution, we will examine geographic variation and interactive effects of air pollution on the associations tested. Moreover, the study will assess whether pregnant women with certain chronic diseases, those taking heat-sensitizing medications, those of low socioeconomic status, those who smoke or drink alcohol, or those with outdoor occupations are more vulnerable to extreme weather conditions. Finally, we will estimate weather-attributable risks for pregnant women and women with certain characteristics, project the birth outcome burden of climate change, and develop vulnerability maps. We will use the National Birth Defects Prevention Study (NBDPS), the largest US population-based case-control study of potential risk factors of birth defects. The birth defect cases include infants with confirmed, selected major birth defects excluding genetic causes (N=23,333) and the controls are non-malformed live-born infants, randomly selected from each center (N= 8,494 controls). Other pregnancy outcomes will be selected from within the NBDPS control group, such as preterm (< 37 weeks) including severe preterm (<32 weeks) and moderately preterm (32-37 weeks), and small-for-gestational-age (below 10% of birth weight for gestational age). Extreme weather indicators defined by the 90th percentile of average summer temperature or the 10th percentile of winter temperature will be evaluated by intensity, duration, frequency, and timing. Other indicators including heat waves and cold spells, the full spectrum of temperature, humidity, air pressure and wind as well as a composite weather index using the Spatial Synoptic Classification system will also be examined. A two-stage Bayesian hierarchical model will be used to first examine the association in each region and then to control for regional characteristics to obtain a nationwide estimate. K-means cluster analysis and Monte Carlo methods will be used to estimate weather factor clusters and uncertainty, respectively. The findings may identify a vulnerable population which has been ignored, and thereby guide climate intervention and adaptation. The multidisciplinary research team has a unique opportunity to use the data already collected and geo-coded through the NBDPS and other ongoing projects, which ensures the project is feasible and sustainable.