AMBIENT AIR POLLUTION EXPOSURE DURING PREGNANCY AND LONGITUDINAL FETAL GROWTH

越来越多的研究强调了空气污染物暴露与出生时胎儿生长之间的负相关[1,2]，但人体测量出生数据无法评估胎儿生长模式。此外，出生体重不能清楚地反映胎儿生长受限bb0。Eunice Kennedy Shriver国家儿童健康与人类发展研究所（NICHD）胎儿生长研究不仅有大量低风险单胎、肥胖和双绒毛膜双胎妊娠的纵向生长数据，而且还发现在美国四个种族的单胎低风险组bbb中胎儿生长存在显著差异。在美国，空气污染暴露[5]和妊娠期高血压疾病[6]因母亲种族而异。这为研究不同种族/民族环境暴露对胎儿生长的潜在影响以及探索改变生长的潜在生物学机制创造了一个独特的机会。超声测量已被用于评估空气污染物对胎儿发育的影响，但很少有纵向数据，之前的研究只有1-3个测量，而我们的研究中怀孕期间有6个测量。这些详细的纵向数据将使我们能够突出胎儿生命中对环境污染物的潜在敏感期。

An increasing number of studies highlight an inverse association between air pollutant exposure and fetal growth estimated at birth [1, 2], but anthropometric birth data does not allow assessment of fetal growth patterns. Furthermore, birth weight does not clearly reflect fetal growth restriction [3]. The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies not only have longitudinal growth data on a large number of low-risk singleton, obese and dichorionic twin pregnancies, but also found significant differences in fetal growth among four US ethnic groups in the singleton low-risk group [4]. Both air pollution exposure [5] and hypertensive disorders of pregnancy [6] vary by maternal race/ethnicity in the US. This creates a unique opportunity to investigate potential variations in fetal growth related to environmental exposure by race/ethnicity as well as to explore potential biologic mechanisms for altered growth. Ultrasound measurements have been used to assess the effects of air pollutants on fetal development but rarely with longitudinal data, and prior studies have had 1-3 measures available compared to the six measures during pregnancy in our study. This detailed longitudinal data will allow us to highlight potential periods of sensitivity to environmental contaminants during fetal life. Our overall goal is to study the association of prenatal air pollution exposure on longitudinal fetal growth including estimated fetal weight, fetal body composition and organ volumes using NICHD Fetal Growth Studies ultrasound measurements. We will also investigate clinical maternal blood pressure and uterine artery Doppler results to provide insights into potential biologic mechanisms. To accomplish this, we propose to assemble the residential zip code data from all NICHD Fetal Growth Study cohorts (singleton, twin and obese), geo-code those zip code centroids in collaboration with the National Cancer Institute (NCI) Intramural Research Program and develop air pollution exposure scenarios using existing data and in collaboration with spatial modelers at NCI. Original study consent forms have been reviewed and the NICHD is not permitted to hold personally identifiable information, such as address, but zip codes are permitted. This has been determined to be Non-Human Subjects Research by the NIH Institutional Review Board (see Appendix 1).