Characterizing the Relationship between Uterine Activity and Placental Function Across Pregnancy with MRI

用 MRI 表征妊娠期子宫活动与胎盘功能之间的关系

• 批准号: 10673962
• 负责人: Esra Abaci Turk
• 金额: $ 26.94万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10673962
• 关键词: Acute; Affect; Animal Model; Animals; Blood Flow Velocity; Blood Pressure; Blood Vessels; Blood flow; Brain; Cesarean section; Characteristics; Chronic; Data; Deceleration; Development; Doppler Ultrasound; Electric Capacitance; Emergency Situation; Event; Fetal Growth Retardation; Fetal Heart Rate; Fetal Monitoring; Fetal Movement; Fetal Reduction; Fetus; Functional Magnetic Resonance Imaging; Functional disorder; Future; Gases; Goals; Health; Heart Rate; Human; Hypoxia; Individual; Liver; Magnetic Resonance Imaging; Maps; Mediating; Methods; Minor; Monitor; Motion; Organ; Outcome; Oxygen; Oxygen Consumption; Partial Pressure; Pathology; Perfusion; Personal Satisfaction; Placenta; Pregnancy; Resistance; Risk; Signal Transduction; Stress; Stress Tests; Testing; Time; Tissues; Uterine Contraction; Uteroplacental Circulation; Uterus; Variant; adverse outcome; antenatal; blood oxygen level dependent; falls; fetal; fetal blood; fetus at risk; heart rate monitor; improved; in utero; intrapartum; novel therapeutics; oxygen transport; pharmacologic; pressure; regional difference; respiratory; response; spatiotemporal; stillbirth; tool; wasting

PROJECT SUMMARY / ABSTRACT The placenta is a vital fetal organ that serves to oxygenate, nourish, and remove waste from fetal blood in utero. Robust maternal perfusion is essential for this function and requires high capacitance, slow blood flow to the placenta. Maternal-placental perfusion can be temporarily compromised by uterine contractions, which occur throughout pregnancy, also known as Braxton Hicks contractions. Healthy fetuses with normally developed placentas have enough placental reserve capacity that Braxton Hicks contractions and minor vascular pathology do not significantly affect necessary placental oxygen transport. However, in dysfunctional placentas with poor reserve (as in some placentas associated with intrauterine growth restriction-IUGR) these events may lead to hypoxic stress. There is a lack of information and quantitative data regarding the effect of antepartum uterine activity (Braxton Hicks contractions) in human pregnancies and whether these findings may help to characterize placental reserve and function and inform development of future tests to identify fetuses at risk for adverse outcomes during delivery mediated by placental dysfunction. New methods to assess uteroplacental function in humans and the impact of contractions on fetal respiratory exchange across pregnancy in pregnancies with normally growing and IUGR fetuses are needed. Here, we will characterize Braxton Hicks contractions across gestation, analyze spatiotemporal changes in placental oxygenation during these contractions and monitor the effect of these placental oxygenation changes on fetal movement and organ oxygenation via MRI. Our hypothesis is that the change in placental flow during Braxton Hicks contractions may have a larger impact on placental oxygen transport for IUGR fetuses compared to normally growing ones. If successful we will have identified placental and fetal MR signal changes during contractions as a possible method to understand individual placental reserve. Such understanding may enable the development of novel therapies and the ability to monitor changes in these dynamics is critical to the assessment of the impact of novel therapies. Towards this end, we propose the following specific aims: Aim 1: Characterize Braxton Hicks contractions and the associated change in placental oxygenation across gestation in pregnancies with normally growing and IUGR fetuses. We will characterize placental oxygenation using T2* mapping approach and analyze regional differences in placental T2*. Then we will compare and correlate differences in pregnancies with normally growing and IUGR fetuses. Aim 2: Determine the impact of placental oxygenation change during Braxton Hicks contractions on fetal motion and brain and liver oxygenation in pregnancies with normally growing and IUGR fetuses. We will track fetal motion and characterize fetal brain and liver oxygenation using T2* mapping. Then we will compare and correlate differences in pregnancies with normally growing and IUGR fetuses.

项目摘要 /摘要 胎盘是一个重要的胎儿器官，可用于氧合，滋养和清除胎儿中的废物 子宫。强大的母体灌注对于此功能至关重要，需要高电容，缓慢的血液流向 胎盘。子宫收缩可能会暂时损害产妇灌注，这 在整个怀孕期间都发生，也称为Braxton Hicks收缩。正常健康的胎儿 发达的胎盘具有足够的胎盘储备能力，可以使收缩和次要 血管病理不会显着影响必要的胎盘氧运输。但是，功能失调 储量较差的胎盘（如某些与宫内生长限制相关的胎盘 - iugr） 事件可能导致低氧应激。缺乏有关有关影响的信息和定量数据 在人类妊娠中的情况下，子宫脑的活动（Braxton Hicks收缩）以及这些发现是否可以 帮助表征胎盘储备和功能并为未来测试的开发提供信息，以识别胎儿 胎盘功能障碍介导的递送过程中不良结果的风险。评估的新方法 人类的子宫术功能以及宫缩对胎儿呼吸道交换的影响 怀孕的怀孕正常增长，需要IUGR胎儿。在这里，我们将描述 布拉克斯顿（Braxton）在妊娠之间收缩，分析​​胎盘氧合的时空变化 这些收缩并监控这些胎盘氧合对胎儿运动和器官的影响 通过MRI充氧。我们的假设是胎盘流的变化在Braxton Hicks收缩期间 与正常生长的胎盘相比，可能对IUGR胎儿的胎盘氧运输的影响更大。 如果成功的话，我们将在收缩期间确定胎盘和胎儿MR信号变化 了解个人胎盘储备的方法。这种理解可以使新颖的发展 疗法和监测这些动态变化的能力对于评估的影响至关重要 新疗法。为此，我们提出以下特定目的：目标1：表征布拉克斯顿·希克斯（Braxton Hicks） 收缩和相关的胎盘氧合在怀孕期间妊娠的胎盘氧合发生变化 通常增长和iugr胎儿。我们将使用T2*映射方法来表征胎盘氧合 并分析胎盘T2*的区域差异。然后，我们将比较并关联 怀孕正常增长和IUGR胎儿。目标2：确定胎盘氧合的影响 Braxton Hicks在胎儿运动，脑和肝脏氧合妊娠期间的变化 通常增长和iugr胎儿。我们将跟踪胎儿运动并表征胎儿大脑和肝脏 使用T2*映射氧合。然后，我们将比较和关联怀孕的差异 生长和iugr胎儿。