FETAL VELOCIMETRY AND AMINO ACID TRANSPORT IN PREGNANCY

该项目的具体目标包括正常的临床研究。 妊娠和妊娠合并胎儿生长受限。 这些研究包括两个方面：1)改进了对 使用新的胎儿监护技术和2)研究的临床严重度 用稳定同位素方法学研究氨基酸的运输和代谢。 直接测量脐静脉血流量的作用比较 动脉血流速度测量和胎儿血液化学 围绕临床严重程度分类的框架进行检查。 同样，从单个胎儿器官获得的额外信息 静脉导管、胎儿肝静脉、胎儿静脉的血流速度测量研究 股动脉、胎儿大脑中动脉也与胎儿比较 脐动脉血流速度测定仪和胎儿化学。智能网的研究 体内氨基酸胎盘转运和代谢是对我们的 观察到胎儿的氨基酸浓度显著地 胎儿生长减少限制了怀孕。非稳定状态 利用稳定的必需和非必需氨基酸异构体的研究 计划进行脐带穿刺术的孕妇体内酸类检查 不同氨基酸基团的转运：a)定义不同的 它们在体内的相对转运速度和b)测试氨基 与正常妊娠相比，FGR孕妇的胃酸转运减少 所有氨基酸或特定亚群的妊娠。稳态稳定 同位素方法学也被用来测试胎儿/母亲 输入的氨基酸稳定异构体的富集率 FGR妊娠的母体循环较低，反映了下降 运输和蛋白质周转增加。母性关系 正常和FGR妊娠的脐血摄取浓度也是 利用脐动静脉血药浓度数据进行调查 剖宫产时间的差异。所有的代谢数据都是 与FGR妊娠临床严重程度分类的比较 使用我们之前发布的标准。

The specific aims of this project involve clinical studies in normal pregnancies and pregnancies complicated by fetal growth restriction. The studies cover two aspects: 1) improvements in the classification of clinical severity using new fetal surveillance techniques and 2) studies of amino acid transport and metabolism using stable isotope methodology. The role of direct measurements of umbilical venous blood flow compared to arterial velocimetry measurements and fetal blood chemistry is examined around the framework of the classification of clinical severity. Similarly, the additional information acquired from single fetal organ velocimetry studies of the ductus venosus, fetal hepatic veins, fetal femoral artery, fetal middle cerebral artery are also compared to fetal umbilical arterial velocimetry and fetal chemistries. The studies of in vivo amino acid placental transport and metabolism is a follow up on our observations that fetal amino acid concentrations are significantly reduced in fetal growth restricted pregnancies. A non steady state study utilizing stable isoptomers of essential and non essential amino acids in pregnant women scheduled for cordocentesis examines in vivo transport for different groups of amino acids: a) to define differences in their relative rates of transport in vivo and b) to test whether amino acid transport is reduced in FGR pregnancies compared to normal pregnancies for all amino acids or a specific subset. Steady state stable isotope methodology is also used to test whether the fetal/maternal enrichment ratios for stable isoptomers of amino acids infused in the maternal circulation is lower in FGR pregnancies reflecting decreased transport and increased protein turnover. The relationship of maternal concentration to umbilical uptake for normal and FGR pregnancies is also investigated utilizing data on umbilical arteriovenous concentration differences at the time of cesarean section. All metabolic data are compared to the classification of clinical severity in FGR pregnancies using criteria we have previously published.