Parental exposure to ionizing radiation and birth defects

说明(申请人提供)：电离辐射是一种公认的致癌物质，已知会导致染色体断裂，即它是一种致裂物。尽管人类对电离辐射和出生缺陷的研究有限，但在动物实验中，电离辐射已被证明会导致出生缺陷。我们假设，在人类受孕前暴露于电离辐射可能会导致父母一方或双方生殖细胞的染色体异常，导致出生缺陷。此外，孕妇在怀孕早期暴露于电离辐射可能会导致发育中的胚胎中快速分裂的细胞死亡，从而导致出生缺陷。上述途径可能导致许多不同类型的出生缺陷，特别是多发性畸形和染色体异常。本研究的目的是：1)评估母亲从X光检查中暴露于电离辐射与出生缺陷之间的关系；2)评估母亲接触职业性电离辐射源与出生缺陷之间的关系；3)评估父亲接触职业性电离辐射源与出生缺陷之间的关系。这项拟议的研究将基于国家出生缺陷预防研究(NBDPS)8.0版的数据。这项研究设计具有成本效益，利用了国家出生缺陷预防研究收集的现有数据，该研究对超过2.2万名孕妇进行了研究。这项研究将包括对15,000多名患有30多种不同类型出生缺陷的婴儿的母亲和7,173名对照母亲的母亲的访谈数据。在怀孕前三个月或怀孕期间进行的医学成像研究将根据母亲对详细电话采访的反应来衡量母亲暴露在电离辐射中的情况。还将根据对同一访谈中关于母亲和父亲职业的详细问题的答复来衡量母亲和父亲的职业暴露。为了对母亲和父亲对职业电离辐射源的暴露进行分类，我们计划使用职业暴露矩阵(JEM)，该矩阵是由美国国家癌症研究所(NCI)的穆斯塔法·多塞梅奇开发的，专门针对职业电离辐射源。总而言之，我们建议对电离辐射和出生缺陷的职业和医学来源进行最大、最具统计能力的人群研究之一。 与公共健康相关：这项研究将确定暴露在X光、CAT扫描和其他类型医学成像辐射下的妇女是否会增加生育30种不同类型出生缺陷的婴儿的风险。它还将确定在工作场所暴露于辐射的女性和男性是否会增加生育30种不同类别出生缺陷的婴儿的风险。

DESCRIPTION (provided by applicant): Ionizing radiation is a well-established carcinogen and is known to cause breakage of chromosomes, i.e. it is a clastogen. Although human studies of ionizing radiation and birth defects are limited, ionizing radiation has been shown to cause birth defects in animal studies. We hypothesize that in humans exposure to ionizing radiation immediately prior to conception may induce chromosomal abnormalities in the germ cells of one or both parents, resulting in birth defects. Further, maternal exposure to ionizing radiation in early pregnancy may result in the death of rapidly dividing cells in the developing embryo resulting in a birth defect. The pathways described above may contribute to the etiology of many different types of birth defects, especially multiple anomalies and chromosomal abnormalities. The aims of this study are: 1) To assess the association between maternal exposure to ionizing radiation from x-ray procedures and birth defects 2) To assess the association between maternal exposure to occupational sources of ionizing radiation and birth defects and 3) To assess the association between paternal exposure to occupational sources of ionizing radiation and birth defects. The proposed study will be based on data from version 8.0 of the National Birth Defects Prevention Study (NBDPS). The study design is cost-effective, utilizing existing data collected by the National Birth Defects Prevention Study on over 22,000 pregnant women. This study will include data from maternal interviews on over 15,000 mothers of infants with over 30 different categories of birth defects and 7,173 control mothers. Maternal exposure to ionizing radiation from medical imaging studies performed in the three months before conception or during pregnancy will be measured based on maternal responses to a detailed telephone interview. Maternal and paternal occupational exposures to ionizing radiation will also be measured based on responses to detailed questions on maternal and paternal occupations from the same interview. In order to classify maternal and paternal exposures to occupational sources of ionizing radiation, we plan to use a job-exposure matrix (JEM) that is specific to occupational sources of exposure to ionizing radiation and has been developed by Mustafa Dosemeci at National Cancer Institute (NCI). In summary we propose to conduct one of the largest most statistically powerful population based studies of occupational and medical sources of ionizing radiation and birth defects. PUBLIC HEALTH RELEVANCE: This study will determine whether women who are exposed to radiation from x-rays, CAT scans and other types of medical imaging are at an increased risk of having infants with 30 different categories of birth defects. It will also determine whether women and men who are exposed to radiation in their workplace have an increased risk of having infants with 30 different categories of birth defects.