监测胎儿脑血流阻力指标预测胎儿宫内缺氧

胎儿宫内缺氧是导致胎儿窘迫、围产儿死亡的主要原因。本研究运用彩色多普勒产前监测胎儿大脑中动脉（MCA）血流速波，计测血流的S／D值、脉搏指数（PI）值、阻力指数（RI）值，（S／D、PI、RI值简称阻力指标）。结果表明：胎儿MCA血流S／D值＜4、PI值＜1．6、RI值＜0．06时，提示胎儿宫内缺氧。正常妊娠组胎儿宫内缺氧者14．2％，妊高征组胎儿宫内缺氧者占46．3％，明显高于正常妊娠组（P＜0．01），IUGR组胎儿宫内缺氧者占52．6％，明显高于正常妊娠组（P＜0．01）。产前直接监测胎儿大脑中动脉血流阻力指标，厂解胎儿颅脑血循环状况，预测胎儿宫内缺氧，及早发现异常，及时防治胎儿窘迫，降低围产儿死亡率，对提高围产医学质量、优生具有实用价值。     

妊娠高血压征胎儿大脑中动脉和脐动脉阻力指标比值检测的临床价值

目的探讨妊娠高血压征（妊高征）胎儿大脑中动脉（MCA）和脐动脉（UA）阻力指标比值预测胎儿宫内低氧的早期诊断价值。方法运用彩色多普勒超声（CDFI）检测76例正常妊娠和36例妊高征胎儿MCA和UA阻力指数（RI）、搏动指数（PI）及S/D值。然后计算MCA和UA各指标比值。结果妊高征胎儿UA阻力指标明显高于正常妊娠组（P〈0.01）,MCA阻力指标均低于正常妊娠组（P〈0.05）,MCA和UA阻力指标比值明显低于正常妊娠组（P〈0.01）。当RIMCA/UA〈0.9,PIMCA/UA〈1.0;（SMCA/DMCA）/（SUA/DUA）〈1.3时,提示胎儿宫内缺氧的敏感性、特异性分别为89%、96%。结论胎儿MCA和UA阻力指标比值可早期发现妊高征胎儿宫内低氧状态,在胎儿窘迫发生前作出诊断,具有重要的临床价值。     

胎儿大脑前循环与脐动脉阻力比值与胎心率预测胎儿宫内窘迫的临床价值

选取80例正常妊娠胎儿与40例宫内窘迫的胎儿作为研究对象,分别为正常组与宫内窘迫组,采用彩色多普勒超声检测胎儿的大脑中动脉(MCA)、胎儿脐动脉(UA)的阻力指数(RI)、搏动指数(PI)以及S/D值,并计算胎儿大脑中动脉与胎儿脐动脉的比值。宫内窘迫组胎儿的胎儿脐动脉阻力指标明显高于正常胎儿组,差异明显具有统计学意义(P<0.01),而胎儿大脑中动脉的阻力指数则低于正常胎儿组,差异明显,具有统计学意义(P<0.05),宫内窘迫组胎儿的胎儿脐动脉与胎儿大脑中动脉的阻力比值明显高于正常胎儿组(P<0.01)。以(RIUA/MCA)>1.00,(PIUA/MCA)>1.00,(SUA/DUA)/(SMCA/DMCA)>0.60为标准,则可以提示胎儿宫内窘迫的敏感性与特异性分别为90.0%和96.0%。宫内窘迫组胎心率不在120~160次/min的正常氛围之内。胎儿大脑前循环脐动脉阻力比值计算与胎心率检测并联合胎心率检测,对于预测胎儿宫内窘迫具有较高的敏感性与特异性,能够作为胎儿宫内窘迫的可靠诊断标准,具有临床推广应用的价值。     

彩色多普勒超声在帆状胎盘单胎妊娠中的诊断价值

【目的】探讨彩色多普勒超声在帆状胎盘单胎妊娠中的诊断价值。【方法】回顾性分析2012年3月至2015年4月本院收治的、经病理学诊断为帆状胎盘的单胎妊娠孕妇55例,根据妊娠结局将孕妇划分为结局良好组（31例）、结局不良组（24例）,比较两组胎儿脐动脉收缩末期峰值与舒张末期峰值比值（S／D ）及阻力指数（RI）。【结果】55例产妇中有48例经彩超诊断为帆状胎盘,诊断符合率为873．％,误诊率为91．％,漏诊率为36．％;妊娠结局不良组脐动脉S／D及RI均明显高于结局良好组,随胎儿脐动脉S／D及RI增高,妊娠结局不良率明显升高,上述差异均有显著性意义（ P ＜00．5）。【结论】彩色多普勒超声是诊断帆状胎盘的有效手段,检测胎儿脐动脉血流参数有助于预测妊娠结局,值得关注。     

彩超对妊娠大于41周胎儿脑及脐动脉血流检测的临床意义

目的：探讨妊娠大于４１周胎儿脑及脐动脉血流检测的临床意义。方法：对３８例妊娠满４１～４２周胎儿大脑中动脉（ＭＣＡ）、脐动脉（ＵＡ）血流阻力指数ＲＩｍｃＡ和ＲＩｕＡ及其比值，与同期孕周＜４１周足月妊娠组和孕周满４２周过期妊娠组比较。结果：妊娠４１周组胎儿ＲＩｍｃＡ和ＲＩｕＡ与足月妊娠组相似，但ＲＩｍｃＡ／ＲＩｕＡ明显低于足月妊娠组（Ｐ＜０．０５），当ＲＩｍｃＡ／ＲＩｕＡ≤１．１０时，胎儿预后不良发生率明显上升（Ｐ＜０．０１）。结论：提示检测妊娠满４１～４２周胎儿ＲＩｍｃＡ／ＲＩｕＡ值，对了解宫内胎儿状况，预测围产儿预后，有临床指导意义     

超声检测胎儿脐动脉血流对预测帆状胎盘孕妇预后的价值

目的 超声检测胎儿脐动脉血流对预测帆状胎盘孕妇预后的价值.方法 95例单胎妊娠合并帆状胎盘孕妇,根据妊娠结局分为妊娠结局良好组51例和不良组44例;孕检正常的孕妇100例为对照组,应用脉冲多普勒获得胎儿脐动脉收缩末期峰值与舒张末期峰值的比值（S/D）,测量阻力指数.结果 妊娠结局不良组脐动脉S/D和阻力指数高于对照组及妊娠结局良好组 （P＜0.05）.随着胎儿脐动脉S/D增高,胎儿分娩周数提前,胎儿妊娠结局不良率增高.S/D＜3时,胎儿宫内情况良好;S/D为3～4时,胎儿预后不良率约29.4％,其中以轻度不良为主;S/D＞4时,胎儿预后不良率87.5％.结论 超声提示帆状胎盘时,胎儿脐动脉血流参数对监测胎儿宫内情况及预测胎儿妊娠结局具有一定的临床价值.     

彩色多谱勒对IUGR脐动脉血流的检测

目的：应用彩色多谱勒检测正常妊娠和胎儿宫内发育迟缓（以简称ＩＵＧＲ）的脐动脉血流指标ＰＩ、ＲＩ、Ｓ／Ｄ值。材料和方法：应用彩色多谱勒检测了２００例正常妊娠和１１１例ＩＵＧＲ的脐动脉血流,孕周从２６－４１周。结果：正常妊娠组及ＩＵＧＲ组的脐动脉血流指标均随妊娠周数的增高而降低,但ＩＵＧＲ组的脐动脉血流ＰＩ、ＲＩ、Ｓ／Ｄ值明显高于正常妊娠组（Ｐ〈０．０１）。孕３０周后,脐动脉血流Ｓ／Ｄ值〉４,揭示胎儿预后不良。结论：脐动脉血流检测不仅是胎儿监护的一种方法,而且可作为诊断ＩＵＧＲ的一个指标及对估计胎儿预后有一定的临床价值。     

胎儿宫内发育迟缓时脐动脉血流阻力与局部一氧化氮含量及合酶的关系

目的：了解胎儿宫内发育迟缓(IUGR)脐动脉血流阻力与母血、脐血一氯化氮(N0)含量、一氧化氮合酶(NOS)的关系，探讨局部N0含量及N0S在胎儿宫内发育迟缓发病中的作用。方法：对200年7月至2001年12月共23例妊娠合并胎儿宫内发育迟缓孕妇及23例正常孕妇(对照组)的母血及脐血中N0含量、胎盘组织NOS以及脐动脉血流阻力(S／D)进行测定，探讨局部N0含量及NOS在胎儿宫内发育迟缓发病中的作用。结果：妊娠合并胎儿宫内发育迟缓患者母血及脐血N0水平均低于正常对照组(P＜0．01)，胎盘组织HOS水平均低于正常对照组(P＜0．05)3两组脐血N0水平均高于母血N0水平(P＜0．01)；两组母血与脐血N0水平呈正相关，对照组r=0．79，P＜0．01，IUGR组r＝0．43，P＜0．05；妊娠合并胎儿宫内发育迟缓患者组脐动脉血流阻力(S／D)明显高于正常对照组(P＜0．05)；国产儿异常的发生率也显著高于正常对照组；脐血N0水平、胎盘组织NOS与脐动脉S／D值、新生儿体重无显著相关性。结论：引起IUGR的原因可能是多方面的，而N0合成减少只是其中的一个环节。     

脐动脉血流速率检测在胎儿监护中的作用

目的评价脐动脉收缩期最大血流速度（Ｓ）与舒张末期血流速度（Ｄ）的比值（Ｓ／Ｄ值）在胎儿监护中的作用。方法对１２７例高危孕妇及１４５例低危孕妇进行脐动脉Ｓ／Ｄ值测定，并追踪观察胎儿妊娠结局。结果高危妊娠组Ｓ／Ｄ值异常阳性率及胎儿窘迫、新生儿窒息的发生率（分别为３１．５０％、４７．９２％、１４．５８％）明显高于低危妊娠组（分别为５．５２％、１２．５９％、１．３４％））（Ｐ＜０．０１）。该项检测对胎儿生长迟缓（ＩＵＧＲ）及妊高征有较高的敏感性（分别为８０％和５０％）。结论脐动脉Ｓ／Ｄ值异常提示子宫胎盘血流灌注下降，血管阻力增加，可作为胎儿监护的一项有效指标，但需与Ｂ超等检测手段联合应用，使诊断结果更完善。     

胎儿宫内发育迟缓孕妇经高压氧治疗后子宫胎盘的血流变化

目的：探讨高压氧对胎儿宫内发育迟缓（IUGR）孕妇子宫动脉及脐动脉的时间平均血流速度（TAV）及血流量（Q）的影响。方法：检测正常妊娠26例,IUGR孕妇24例的子宫动脉及脐动脉TAV、Q值,将24例伴有子宫动脉及脐动脉TAV、Q血流异常的IUGR孕妇作高压氧治疗,测定治疗前后子宫动脉及脐动脉TAV、Q的血流动力学变化。结果：IUGR组孕妇子宫动脉及脐动脉TAV、Q值显著低于正常组（P＜0.05）。经高压氧治疗后子空动脉及脐动脉TAV、Q值显著增高（P＜0.05）。结论：高压氧治疗能有效地改善IUGR孕妇的子宫胎盘血液循环,改善胎盘功能,促进胎儿生长发育。     

脐带绕颈胎儿脐动脉及大脑中动脉超声血流参数的特点及与胎儿宫内窘迫的相关性分析

目的探讨脐带绕颈胎儿脐动脉(UA)及大脑中动脉(MCA)超声血流参数的特点及与胎儿宫内窘迫的相关性。方法将106例胎儿脐带绕颈孕妇、100例正常孕妇分别纳入脐带绕颈组、非脐带绕颈组。根据不同孕周、是否发生胎儿宫内窘迫对脐带绕颈组孕妇进行再次分组,分别为28~36周组(52例)、≥37周组(54例);宫内窘迫组(28例)、非宫内窘迫组(78例)。比较各组UA、MCA的RI、PI、S/D。分析UA、MCA超声血流参数与胎儿宫内窘迫的相关性。结果脐带绕颈组UA、MCA的RI、PI、S/D均高于非脐带绕颈组(P<0.05)。28~36周组UA、MCA的RI、PI、S/D均低于≥37周组(P<0.05)。宫内窘迫组UA的PI、S/D高于非宫内窘迫组,MCA的RI、PI、S/D高于非宫内窘迫组(P<0.05)。Logistic回归分析结果显示,UA、MCA的PI、RI、S/D与胎儿宫内窘迫存在明显相关性(P<0.05)。结论脐带绕颈胎儿UA、MCA超声血流参数(RI、PI、S/D)均高于非脐带绕颈胎儿,且孕晚期更为突出,UA及MCA的RI、PI、S/D与胎儿宫内窘迫呈高度相关。     

妊娠期高血压病胎儿肾动脉和大脑中动脉阻力指标比值预测胎儿缺氧

目的探讨妊娠期高血压疾病胎儿肾动脉和大脑中动脉阻力指标比值预测胎儿宫内缺氧的价值。方法应用彩色多普勒超声检测65例正常妊娠和46例妊娠期高血压疾病胎儿肾动脉（RA）、大脑中动脉（MCA）阻力指数（RI）、搏动指数（PI）及S／D值，计算RA与MCA各指标比值。结果妊娠期高血压疾病组胎儿RA阻力指标均明显高于正常对照组（P〈0．01），MCA阻力指标均低于正常对照组（P〈0．05），RA和MCA阻力指标比值高于正常组（P〈0．01）。以（RIRA，MCA、）〉1．11，（PIRA，MCA）〉1．30，（SRA／DRA）／（SMCA／DRA）〉1．44提示胎儿宫内缺氧的敏感性、特异性分别为89％、92％。结论胎儿肾动脉和大脑中动脉阻力指标比值预测胎儿宫内缺氧具有较高的敏感性和特异性。     

彩色多普勒超声检测胎儿脐动脉及大脑中动脉血流频谱对预测宫内窘迫的临床意义

目的探讨运用彩色多普勒检测胎儿脐动脉(UA)及大脑中动脉(MCA)血流频谱相关数值对预测胎儿宫内窘迫的临床意义。方法选取2013年9月至2015年3月随机分层抽取行中晚期孕检孕妇44例,其中健康孕妇组35例,宫内窘迫孕妇组11例,应用彩色多普勒超声检测上述两组胎儿UA及MCA的阻力指数(RI)、血流搏动指数(PI)、收缩期与舒张期流速比(S/D)。结果与健康孕妇组相比,宫内窘迫孕妇组胎儿UA的RI、PI、S/D明显增高,而MCA各血流频谱指标明显下降,差异均有统计学意义(P0.05)。结论通过检测中晚期妊娠胎儿UA及MCA各血流频谱的指标有助于发现胎儿宫内窘迫的发生,为提高围产质量提供检查手段。     

高危妊娠胎儿肾动脉、大脑中动脉搏动指数比值预测胎儿缺氧

目的 应用彩色多普勒超声技术检测胎儿大脑中动脉(MCA)和肾动脉(RA)血流动力学指标,探讨高危妊娠胎儿RA和MCA的搏动指数比值预测胎儿宫内缺氧的临床应用价值.方法 选取晚期正常妊娠孕妇95例,晚期高危妊娠孕50例,检测两组胎儿MCA和RA的血管收缩期峰值速度(S)与舒张末期流速(D)比值、阻力指数(RI)及搏动指数(PI),同时计算两组RA与MCA的PI比值,并将以上检测值与围产儿缺氧指标进行比较.结果 高危组胎儿MCA脉各阻抗指标均低于正常妊娠组(P＜0.01);RA各阻抗指标均高于正常妊娠组(其中PI、RI值P＜0.01,S/D值P＜0.05);RA和MCA搏动指数比值高于正常组(P＜0.01).以PIRA/MCA＞1.50提示胎儿宫内缺氧的敏感性和特异性分别为86.0%和91.5%.结论 胎儿RA和MCA的搏动指数比值预测胎儿缺氧具有较高的敏感性和特异性.     

远程胎心监护联合超声检测对胎儿宫内缺氧的预测效果分析

目的观察远程胎心监护联合超声检测对胎儿宫内缺氧的预测效果,探讨最佳诊断措施。 方法选取2016年6月至2017年6月杭州市妇产医院收治的行超声检查且住院分娩的孕晚期孕妇210例,65例经临产前及产后诊断证实为宫内缺氧,将其作为观察组,同时期本院体检中心145例健康妊娠者,作为对照组,对所有研究对象均行远程胎心监护以及超声检测。测得大脑中动脉（MCA）、脐动脉（UA）以及大脑中动脉/脐动脉（MCA/UA）中的血流速度的比值（S/D）、阻力指数（RI）、搏动指数（PI）测值。观察组与对照组MCA、UA、MCA/UA等参数比较采用t检验;远程胎心监护情况（有反应型、无反应型、可疑型）观察组与对照组比较采用χ²检验。 结果观察组的胎心监护异常者58例,约占87.93%;对照组异常者20例,约占13.79%,两者比较,观察组高于对照组,差异有统计学意义（χ²=214.925,P<0.001）。与对照组比较,观察组的MCA中的S/D、RI、PI均降低明显,UA以及MCA/UA中的S/D、RI、PI均增加明显,差异均有统计学意义（t=8.91、10.23、8.46、5.20、4.66、16.57、10.99、14.71、13.8,P均<0.001）,进行指标的两两组合,结果发现,联合诊断的敏感度、Youden指数均最高。 结论远程胎心监护联合超声检测可较好的预测胎儿宫内缺氧情况,具有较好的应用价值。     

Fetal adrenal artery velocimetry measurements in appropriate-for-gestational age and intrauterine growth-restricted fetuses.

OBJECTIVE: To investigate adrenal artery blood flow in the fetus. DESIGN AND METHOD: Sixty-two appropriate-for-gestational-age (AGA) and 20 intrauterine growth-restricted (IUGR) fetuses were recruited to this cross-sectional study between 22 and 42 weeks of pregnancy in a tertiary referral fetal medicine unit of a university hospital. ENDPOINTS: Doppler velocimetry of the fetal adrenal, umbilical (UA), renal and middle cerebral arteries (MCA). Pulsatility index (PI), resistance index (RI), peak systolic velocity (PSV), time-averaged maximum velocity (TAMXV) and cerebroplacental ratio (MCA RI/UA RI; CPR). Obstetric outcome. RESULTS: The adrenal artery was detected in 82% of the fetuses. All flow velocity waveforms obtained from the adrenal artery indicated low impedance blood flow. No significant changes in PI, RI, PSV and TAMXV occurred with advancing gestation. The blood flow parameters of the adrenal artery did not differ between AGA and IUGR fetuses. In five IUGR fetuses with signs of redistribution of cardiac output in favor of the brain, the adrenal artery velocimetry results were unremarkable. The adrenal artery PI, RI, PSV and TAMXV values were higher in female fetuses than in male fetuses (P < 0.05). A relationship was observed between the velocity measurements and the estimated fetal weight (P < 0.01). CONCLUSIONS: The fetal adrenal artery could be readily detected. We observed no redistribution of blood flow in favor of the fetal adrenals in IUGR fetuses which were not severely compromised.     

Potential for diagnosing imminent risk to appropriate- and small-for-gestational-age fetuses by Doppler sonographic examination of umbilical and cerebral arterial blood flow.

In a prospective study, 215 pregnancies of known gestational age were investigated using Doppler sonography. Multiple pregnancies and pregnancies complicated by fetal malformations were excluded. A pulsed Doppler machine was used to record the flow velocity waveforms in the umbilical artery (UA) and middle cerebral artery (MCA). The pulsatility index (PI) of both vessels and the ratio of PI UA to PI MCA were calculated. A total of 127 pregnancies ended in the birth of appropriate-for-gestational age babies with no perinatal problems; these formed the normal group (Group A). Of the 88 pregnancies which made up the risk group, 17 were appropriate-for-gestational age babies with perinatal problems (Group B), 55 were small-for-gestational-age babies with no perinatal problems (Group C), and 16 were small-for-gestational age babies with perinatal problems (Group D). Normal ranges were calculated based on the results for Group A; the measured values for the risk groups were then compared to these. There were highly significant differences between values obtained from the risk groups and those of Group A with the exception of the umbilical artery in Group B and the middle cerebral artery in Group C. The best results came from the values for MCA in Group B (sensitivity = 71%), UA in Group D (sensitivity = 75%), and the PI ratio UA : MCA in Group D (sensitivity = 81%). The sensitivity for the ratio in Group D increased to 93% if only the last measurement for each patient taken within 14 days of delivery was analyzed. A drop in the MCA PI in appropriate-for-gestational-age fetuses was the best indicator of imminent risk of hypoxemia. The PI ratio of UA : MCA is valuable in monitoring small-for-gestational-age fetuses, particularly those with high UA PI levels, as a rise in the ratio provides an early indication of fetal risk.     

Effect of antenatal glucocorticoid therapy on arterial and venous blood flow velocity waveforms in severely growth-restricted fetuses.

OBJECTIVE: To study the effects of antenatal glucocorticoid (betamethasone) therapy on blood flow velocity waveform patterns in the umbilical artery (UA), middle cerebral artery (MCA) and ductus venosus (DV) in severely intrauterine growth-restricted (IUGR) fetuses. METHODS: Fifty-five severely IUGR fetuses at 24-34 weeks of gestation were included in the study. The effect of antenatal glucocorticoid administration on Doppler findings in the UA, MCA and DV was studied using two statistical approaches, namely paired sample analysis and multilevel analysis. RESULTS: There were no effects of betamethasone on the pulsatility index (PI) of the vessels studied. The only changes noticed during the 14 days of observation were a gradual decrease of PI in the MCA, an increase in the UA-PI/MCA-PI ratio and an increase in the DV-PI. These changes with time may be explained by a progressive and gradual deterioration of the fetal condition. CONCLUSION: Antenatal glucocorticoids (betamethasone) do not affect fetal Doppler waveform patterns of the UA, MCA and DV in severely IUGR fetuses.     

Is Doppler prediction of anemia effective in the growth-restricted fetus?

OBJECTIVE: To evaluate the utility of middle cerebral artery (MCA) and umbilical artery (UA) Doppler to predict anemia in intrauterine growth restricted (IUGR) fetuses. METHODS: Fetuses with an abdominal circumference < 5th percentile had UA and MCA Doppler prior to delivery. The UA pulsatility index (PI), MCA PI, ratio between the MCA/UA PI (cerebroplacental ratio, CPR) and MCA peak systolic velocity (PSV) were measured. A complete blood count was determined from a peripheral venous sample drawn at delivery. Anemia was defined as a hemoglobin value of < 13 g/dL. MCA PSV Z-scores (standard deviation from gestational age mean using references ranges by Mari et al. and Kurmanavicius et al.) were related to hemoglobin using linear regression analysis. In addition, UA absent end-diastolic velocity (AEDV), brain sparing (MCA PI > 2 SDs below gestational age mean), low CPR (> 2 SDs below gestational age mean) and an elevated MCA PSV (> 2 SDs) were evaluated for their predictive accuracy for anemia. RESULTS: Of 97 IUGR neonates 23 were anemic (23.7%). The MCA PSV was significantly related to hemoglobin using either reference range (Mari et al., F = 22.1577, Kurmanavicius et al., F = 21.8188, P < 0.001, respectively). However, using categorical cut-offs as well as regression analysis none of the Doppler parameters could be identified to provide clinically useful prediction of anemia. CONCLUSION: Parameters of MCA and UA vascular impedance and MCA PSV are significantly related to anemia in IUGR neonates. Despite this relationship the predictive accuracy is unacceptable for the clinical application in the setting of IUGR. Altered cardiovascular dynamics in IUGR fetuses may be responsible for this effect.     

彩色多普勒血流动力学指标预测胎儿缺氧及酸中毒的价值

目的： 评价血液动力学指标预测胎儿缺氧及酸中毒的价值。方法： 用彩色多普勒超声检测 ５４ 例正常晚 期妊娠 （正常组） 和 ３６ 例高危妊娠 （高危组） 妇女子宫动脉 （ＵｔＡ） 和胎儿脐动脉 （Ｕｍ Ａ）、大脑中动脉（Ｍ ＣＡ）、肾动脉 （ＲＡ） 的血流速度波型 （ＦＶＷ ｓ）, 并且测定高危组脐动脉血气。结果： 高危组ＵｔＡ、Ｕｍ Ａ、ＲＡ 的阻力指数 （ＲＩ） 搏动指数 （ＰＩ） 及收缩期最大血流速度与舒张末期血流速度的比值 （Ｓ／Ｄ） 均高于正常组, 而Ｍ ＣＡ的ＰＩ及Ｓ／Ｄ 值均明显低于正常组 （Ｐ＜ ００５）。与Ｕｍ Ａ 氧分压 （ＰＯ２） ＞ ２５ｋＰａ 的高危妊娠病例比较, Ｕｍ Ａ ＰＯ２＜２５ ｋＰａ 者ＵｔＡ 的Ｓ／Ｄ 值, Ｕｍ Ａ 的ＰＩ, Ｓ／Ｄ 值以及ＲＡ 的ＲＩ、ＰＩ、Ｓ／Ｄ 值均明显增高, Ｍ ＣＡ 的ＰＩ明显降低 （Ｐ＜００５）。Ｕｍ Ａ 及ＲＡ 的ＰＩ与Ｕｍ Ａ ＰＯ２ 的ｐＨ 值呈负相关, 与二氧化碳分压 （ＰＣＯ２） 呈正相关, Ｍ ＣＡ 的ＰＩ与Ｕｍ Ａ的 ｐＨ、ＰＯ２ 呈正相关, 与ＰＣＯ２ 呈负相关。结论： 高危妊娠胎儿缺氧时, Ｍ ＣＡ 血流阻力降低, 而周围血管, 特别是肾血管血流阻力明显升高。胎儿血液动力学变化与缺氧及酸碱平衡失