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.

项目概要/摘要 胎盘是胎儿的重要器官，负责给胎儿血液供氧、滋养和清除废物。 子宫。强大的母体灌注对于这一功能至关重要，并且需要高容量、缓慢的血流 胎盘。母体胎盘灌注可能会因子宫收缩而暂时受到损害， 发生在整个怀孕期间，也称为布拉克斯顿·希克斯宫缩。胎儿健康正常 发达的胎盘有足够的胎盘储备能力，可以使布拉克斯顿·希克斯宫缩和轻微的宫缩 血管病理学不会显着影响必要的胎盘氧运输。然而，在功能失调的情况下 储备能力差的胎盘（如某些与宫内生长受限 - IUGR 相关的胎盘） 事件可能导致缺氧应激。缺乏关于影响的信息和定量数据 人类妊娠中的产前子宫活动（布拉克斯顿·希克斯宫缩）以及这些发现是否可能 有助于描述胎盘储备和功能的特征，并为未来识别胎儿的测试的发展提供信息 胎盘功能障碍介导的分娩期间不良后果的风险。新的评估方法 人类子宫胎盘功能以及宫缩对胎儿呼吸交换的影响 妊娠正常生长和IUGR胎儿是必要的。在这里，我们将表征 布拉克斯顿·希克斯 (Braxton Hicks) 妊娠期收缩，分析​​妊娠期间胎盘氧合的时空变化 这些宫缩并监测胎盘氧合变化对胎儿运动和器官的影响 通过 MRI 进行氧合。我们的假设是布拉克斯顿·希克斯宫缩期间胎盘流量的变化 与正常生长的胎儿相比，可能对 IUGR 胎儿的胎盘氧气运输产生更大的影响。 如果成功，我们将确定宫缩期间胎盘和胎儿 MR 信号的变化，这是可能的 了解个体胎盘储备的方法。这种理解可能有助于开发新颖的 治疗方法以及监测这些动态变化的能力对于评估治疗的影响至关重要 新疗法。为此，我们提出以下具体目标： 目标 1：塑造 Braxton Hicks 的特征 怀孕期间的宫缩和胎盘氧合的相关变化 正常生长和 IUGR 胎儿。我们将使用 T2* 映射方法表征胎盘氧合 并分析胎盘 T2* 的区域差异。然后我们将比较和关联差异 正常生长和 IUGR 胎儿的妊娠。目标 2：确定胎盘氧合的影响 布拉克斯顿·希克斯宫缩期间胎儿运动以及大脑和肝脏氧合的变化 正常生长和 IUGR 胎儿。我们将跟踪胎儿运动并描述胎儿大脑和肝脏的特征 使用 T2* 映射进行氧合。然后我们将比较和关联怀孕与正常怀孕的差异 生长发育和 IUGR 胎儿。