ANTIOXIDANT STATUS, DIET, AND EARLY PREGNANCY

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 人类的繁殖效率很低，只有不到三分之一的受精卵有可能存活下来进行足月分娩。这些失败绝大多数发生在排卵后的最初几周。这些生殖失败的原因基本上是未知的，但有证据表明，它们可能是母亲暴露的结果，包括怀孕前的营养，这可能会导致对卵母细胞和妊娠周胚胎的侮辱。这项前瞻性流行病学研究的目标是评估与氧化应激增加相关的饮食模式导致延迟怀孕时间或早期丢失的假设。活性氧物种(ROS)与自然流产、先兆子痫、女性胎膜早破和男性精子功能障碍有关。ROS的形成是生化反应和外界因素共同作用的结果。我们建议对100名计划怀孕的健康女性进行一项队列研究。要评估的结果是怀孕时间，定义为从停止避孕到临床公认怀孕的月经周期数，以及早期、未认识到的妊娠丢失。通过检测尿液中的人绒毛膜促性腺激素(HCG)来确定不明原因的妊娠和随后的早期丢失。在怀孕之前，将使用饮食记录和抗氧化剂维生素C、维生素E以及类胡萝卜素的血清分析来评估饮食。将检测两种氧化应激的尿液生物标志物，8-羟基-2‘-脱氧鸟苷和F2β-异前列腺素。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Human reproduction is inefficient with less than one-third of fertilized human eggs likely to survive to produce a term delivery. The great majority of these failures occur in the early weeks after ovulation. The causes of these reproductive failures are substantially unknown, but evidence suggests that they may be a consequence of maternal exposures, including pre-conception nutrition, that may result in insults to the oocyte and periconceptual embryo. The goal of this prospective epidemiologic study is to evaluate the hypothesis that dietary patterns associated with increased oxidative stress result in delayed time-to-pregnancy or early loss. Reactive oxygen species (ROS) have been associated with spontaneous abortion, preeclampsia, and premature preterm rupture of the membranes in women and defective sperm function in men. ROS are formed continuously as a consequence of both biochemical reactions and external factors. We propose to conduct a cohort study of 100 healthy women planning pregnancy. The outcomes to be evaluated are time-to-pregnancy, defined as the number of menstrual cycles from the cessation of contraception to a clinically recognized pregnancy, and early, unrecognized pregnancy loss. Unrecognized pregnancy and subsequent early loss will be determined by measuring urinary human chorionic gonadotropin (hCG). Diet will be assessed prior to conception using diet records and serum assays for the antioxidant vitamins C and E, and the carotenoids. Two urinary biomarkers of oxidative stress, 8-hydroxy-2'-deoxyguanosine and F2¿-isoprostanes will be measured.