Prenatal MF Exposure & Miscarriage Risk Among Women

描述（由申请人提供）：最近发表的两篇论文提出了对怀孕期间暴露于高水平>=16毫克（mG）]磁场（MFs）和流产风险的担忧。工频强辐射无处不在，约75%的孕妇暴露于强辐射水平>= 16mg。因此，如果报告的产前暴露于MFs >=16 mG与流产风险（相对风险范围从1.8到5.7）之间的关联是真实的，它将具有重大的公共卫生影响。为了进一步研究这种关联，我们建议在易感和非易感孕妇中进行一项基于人群的前瞻性队列研究。我们将对有多次流产史的易感女性进行过度取样。正如我们的初步研究所表明的，MF对流产的影响在易感妇女中比在整个怀孕人群中更大。进一步评估易感和非易感妇女之间的MF-流产相关性具有提高检测MF效应的敏感性和提供比较MF效应大小差异的机会的优势。这项研究将在凯撒永久医疗保健计划北加州地区的成员中进行，这是一个每年有32,000名新生儿的群体模式综合医疗保健提供系统。我们将总共招募1000名孕妇：500名有多次流产史，500名没有此类历史。将进行面对面访谈，以收集有关已知流产风险因素的信息。参与者将被要求佩戴测量仪24小时，以记录来自所有来源的个人MF暴露，并记录其活动日记。妊娠结局将通过搜索计算机数据库、查阅医疗图表和电话随访来确定。Cox比例风险回归将用于确定(a)怀孕期间暴露于MF水平=> - 16mg是否会增加流产风险，(b)是否存在剂量-反应关系，(c)早期流产（妊娠< 10周）是否更强，以及(d)有多次流产史和没有多次流产史的女性之间是否存在这种关联。拟议的研究还将显著改善MF暴露测量，包括增强仪表能力、重复测量、识别高MF暴露源和典型一天的测量。我们从最近完成的mf -流产关联研究中获得的经验和专业知识应该为拟议研究的成功提供重要保证。拟议研究的结果将为最近报道的结果提供急需的证实，并促进我们对MF健康影响的理解。

DESCRIPTION (provided by applicant): Two recently published papers have raised concerns about exposure to high levels >=16 milligauss (mG)] of magnetic fields (MFs) during pregnancy and the risk of miscarriage. Power frequency MFs are ubiquitous and about 75% of pregnant women were exposed to MF levels >=16 mG. Therefore, if the reported association of prenatal exposure to MFs >=16 mG with the risk of miscarriage (relative risk ranging from 1.8 to 5.7) is true, it will have significant public health implications. To further examine this association, we propose to conduct a population-based prospective cohort study among susceptible and non-susceptible pregnant women. We will over-sample susceptible women defined as having a history of multiple miscarriages. As demonstrated in our preliminary study, a MF effect on miscarriage is greater among susceptible women than among the overall pregnant population. Further evaluating the MF-miscarriage association among both susceptible and nonsusceptible women has the advantage of increasing the sensitivity of detecting a MF effect and providing an opportunity to compare the difference in the magnitude of the MF effect. The study will be conducted among members of the Kaiser Permanente Medical Care Program Northern California Region, a group-model integrated healthcare delivery system with 32,000 births each year. We will recruit a total of 1,000 pregnant women: 500 with a history of multiple miscarriages and 500 without such a history. In-person interviews will be conducted to collect information on known risk factors for miscarriage. Participants will be asked to wear a meter for 24 hours to capture their personal MF exposure from all sources and to keep a diary of her activities. Pregnancy outcomes will be ascertained through a combination of searching computerized databases, review of medical charts, and telephone follow-up. The Cox proportional hazard regression will be used to determine (a) whether exposure to MF levels =>16 mG during pregnancy increases the risk of miscarriage, (b) whether there is a dose-response relationship, (c) whether this association is stronger for early miscarriage (< 10 weeks of gestation), and (d) whether this association differs between women with and without a history of multiple miscarriages. The proposed study will also significantly improve MF exposure measurements including an enhanced meter capability, repeat measurements, identifying sources of high MF exposure, and measurements on a typical day. Our experience and expertise gained from the recently completed study of MF-miscarriage association should provide significant assurance for the success of the proposed study. The findings from the proposed study will provide much needed confirmation of the recently reported results and advance our understanding of a MF health effect.