MATERNAL CAFFEINE USE IN PREGNANCY OUTCOME

母体咖啡因摄入在不良妊娠结局发病机制中的作用是有争议的。几项研究发现，与不饮用咖啡因的女性相比，饮用咖啡因的女性自然流产和胎儿发育迟缓的风险更高。然而，其他同样做得很好的研究发现咖啡因摄入没有有害影响。此外，一些研究报告称，咖啡因只对吸烟的女性有害。之前关于这个问题的所有研究都依赖于母亲报告的咖啡因使用情况；目前还没有研究使用咖啡因的生物标志物。本项目首先验证了血清咖啡因及其代谢物作为咖啡因摄入量的标志物，然后研究了这些血清标志物作为不良妊娠结局的危险因素。在验证研究中，血清副黄嘌呤被确定为咖啡因摄入量的可接受标记物。作为该项目的一部分，研究人员分析了约450名女性血清中尼古丁代谢物可替宁的浓度，并将结果与她们报告的吸烟情况进行了比较。研究发现，女性在报告自己是否吸烟时非常诚实，但她们的血清可替宁浓度与吸烟量只有适度的相关性。这是两组年龄相差30岁的女性的情况。在这个项目的主要部分，正在比较591名自然流产妇女和2558名活产妇女的血清中咖啡因初级代谢物副黄嘌呤的浓度，这些妇女在怀孕期间与自然流产妇女同时抽取血清。此外，将在这2558名妇女中评估胎儿生长降低与妊娠晚期副黄嘌呤血清浓度之间的关系。自然流产妇女的副黄嘌呤平均浓度高于活产妇女（752 ng/ml vs 583 ng/ml）。进一步的分析表明，这可能是由于少数女性的副黄嘌呤浓度非常高。血清副黄嘌呤浓度高于第95百分位的比值比为1.86 (p<0.01)，但中等浓度与自然流产风险升高无关。这些结果表明，怀孕期间适量摄入咖啡因不会增加自然流产的风险。-咖啡因，自然流产，胎儿生长，流行病学，病例对照研究，生物标志物-人类受试者：访谈，问卷调查或仅调查

The role of maternal caffeine consumption in the pathogenesis of adverse pregnancy outcomes is controversial. Several studies have found that women who consume caffeine are at increased risk of spontaneous abortion and fetal growth retardation compared to non-users. However, other equally well-done studies have found no harmful effects of caffeine consumption. In addition, several studies have reported that caffeine is harmful only among women who smoke. All previous studies of this question have relied on maternally-reported caffeine use; no studies have employed a biomarker for caffeine. This project first validated the use of serum caffeine and its metabolites as a marker for caffeine intake, and then studied these serum markers as a risk factor for adverse pregnancy outcome. In the validation study, serum paraxanthine was determined to be an acceptable marker for caffeine intake. As part of this project, the concentration of cotinine, a metabolite of nicotine, was assayed in the serum of approximately 450 of the women and the results compared to their reported cigarette smoking. Women were found to be very honestin reporting whether they smoked, but their serum concentration of cotinine correlated only moderately with the amount smoked. This was the case for two separate populations of women 30 years apart. In the main part of this project, the serum concentration of paraxanthine, caffeines primary metabolite, is being compared between 591 women experiencing a spontaneous abortion and 2558 women with live births who had serum drawn at the same time of pregnancy as the women with spontaneous loss. In addition, the association between reduced fetal growth and third-trimester paraxanthine serum concentrations will be evaluated among these 2558 women. The mean concentration of paraxanthine was higher in women experiencing a spontaneous abortion than women experiencing a live birth (752 vs 583 ng/ml). Further analysis revealed that this may be explained by a few women with very high concentrations of paraxanthine. The odds ratio for serum paraxanthine concentration greater than the 95th percentile was 1.86 (p<0.01), but intermediate concentrations were not associated with an elevated risk of spontaneous abortion. These results suggest that moderate caffeine consumption during pregnancy does not increase the risk of spontaneous abortion. - caffeine, spontaneous abortion, fetal growth, epidemiology, case-control study, biomarkers - Human Subjects: Interview, Questionaires, or Surveys Only