Savitz David A, Dole Nancy, Herring Amy H
Department of Community and Preventive Medicine, Mount Sinai School of Medicine, New York, USA.
Stat Methods Med Res. 2006 Apr;15(2):93-102. doi: 10.1191/0962280206sm433oa.
Using epidemiology to elucidate the causes of adverse pregnancy outcomes offers unique opportunities and poses distinctive challenges. The context of pregnancy includes contraception and planning, medical interventions altering the natural history, and the tendency for selective participation in demanding research protocols. Several key pervasive issues are considered in detail: 1) the close temporal proximity of determinants and outcomes, which makes separation of causes and effects difficult and introduces the real possibility of reverse causality; 2) non-random allocation of exposure, often done consciously in response to concerns about having a healthy pregnancy or to the health of the pregnancy itself, making confounding a major concern; 3) heterogeneity of pregnancy outcomes, with endpoints such as pregnancy loss and preterm birth arising through diverse pathways that are not easily identified and if grouped, could diminish the magnitude of observed associations; and 4) racial and ethnic disparities, which pose a public health challenge in the USA and offer a potentially important opportunity for identifying preventable causes of adverse pregnancy outcome. Sophisticated biological and statistical methods are needed to advance epidemiologic research in this area.
运用流行病学阐明不良妊娠结局的原因，既带来了独特机遇，也带来了特殊挑战。妊娠背景涵盖避孕与计划、改变自然病程的医学干预措施，以及选择性参与严苛研究方案的倾向。本文详细探讨了几个关键且普遍存在的问题：1）决定因素与结局在时间上紧密相邻，这使得区分因果关系变得困难，并引发了反向因果关系的实际可能性；2）暴露的非随机分配，这通常是出于对孕育健康胎儿的担忧或基于妊娠本身的健康状况而有意识进行的，使得混杂因素成为一个主要问题；3）妊娠结局的异质性，诸如妊娠丢失和早产等终点事件通过多种不易识别的途径产生，如果将其归为一组，可能会削弱所观察到的关联强度；4）种族和民族差异，这在美国构成了一项公共卫生挑战，同时也为识别不良妊娠结局的可预防原因提供了一个潜在的重要契机。需要运用复杂的生物学和统计学方法来推动该领域的流行病学研究。
