正常胎儿出生前后心脏功能变化的分析

目的：探讨胎儿出生前后左右心室收缩及舒张功能的变化。资料与方法：本文分析５０例正常妊娠胎儿２０～４０周左右心室房室瓣口舒张期血流的Ａ／Ｅ比值及主、肺动脉瓣口血流速度的变化，同时比较１４例足月妊娠与４１例出生后新生儿的左右心室舒张收缩功能变化。结果：正常妊娠时，随孕周的增加左右心室房室瓣口血流速度Ａ／Ｅ比值逐渐降低，主动脉及肺动脉瓣口收缩期血流峰速逐渐增加。胎儿出生后左心室舒张期房室瓣口血流速度Ａ／Ｅ比值明显下降，主动脉瓣口血流峰速明显增快；右心室房室瓣口血流及肺动脉瓣口血流速度无明显变化。结论：正常妊娠期左右心室的舒张功能及收缩功能随孕周增加逐渐加强，胎儿出生后左心室舒张功能及收缩功能明显加强，而右心室舒张功能及收缩功能无变化。     

应用多普勒超声在妊娠11+0～14+6周筛查先天性心脏畸形的初步研究

目的 在妊娠早期末和妊娠中期初联合应用二维超声和多普勒超声观察胎儿心脏结构、心内 和心外血流,探索在此阶段多普勒超声在筛查胎儿先天性心脏发育异常中的价值.方法 在妊娠11 +0 ～ 14 +6周进行常规胎儿产前超声检查,结合颈项透明层厚度(NT)和颈部软组织厚度(NF)测量,观察胎儿心脏 大体结构,应用脉冲多普勒超声获取胎儿二尖瓣、三尖瓣和静脉导管血流频谱,并进行相应的血流频谱分析.所有胎儿在妊娠中期进行胎儿超声心动图检查或在出生后进行新生儿超声心动图检查.结果 正常胎儿 335 例,NT 或NF 增厚者9 例,其中1 例在妊娠13 周诊断心脏永存动脉干畸形,引产后病理证实,2 例选择14 周前终止妊娠,2 例妊娠中期超声筛查胎儿其他结构异常选择中期引产,无心脏结构异常,4 例足月分娩,无 心脏结构异常.正常胎儿舒张早期时间(EADT)较舒张晚期时间(ENDT)短,左右心室之间无统计学差异.NT 增厚不伴心脏畸形胎儿仅部分胎儿静脉导管搏动指数(PI)、阻力指数(RI)、收缩期峰值流速与舒张期最 低流速比值(S/D)增高.永存动脉干胎儿左右心室E/A 比值较正常胎儿异常增高或下降,EADT 缩短,ENDT 延长,EADT/ENDT 比值缩小,静脉导管血流波形异常.结论 妊娠13 周后,随着胎儿心脏各个切面的显示 率不断增高,可有针对性地对特殊群体进行早期的胎儿超声心动图检查,筛查严重的先天性心脏畸形.分析 二尖瓣和三尖瓣的血流频谱,判断左右心室的血流动力学变化,并结合观察静脉导管的血流波形,可以辅助 筛查胎儿先天性心脏畸形.如果仅二维超声怀疑心脏结构异常,而心内和心外血流动力学未发生改变者,应 慎重诊断先天性心脏畸形,避免误诊.     

多普勒超声心动图对胎儿心功能的研究

我们利用多普勒超声心动图记录76例孕龄从21周到42周的正常胎儿心脏各瓣膜血流频谱,测量 1.最大血流速度;2.血流频谱积分;3.主动脉、肺动脉血流的加速时间、射血时间;4.二尖瓣、三尖瓣血流的E峰、A峰;计算通过各瓣口的每搏量、心排量。结果显示了多普勒超声心动图研究胎儿心功能的可行性,并进一步证实胎儿循环右心占优势,胎儿循环处于高阻力状态及胎儿心室肌舒张功能减低。     

组织多普勒成像技术评价高危妊娠对胎儿心脏功能影响的临床价值

目的 探讨组织多普勒成像技术在评价高危妊娠胎儿心脏功能的临床价值.方法 应用组织多普勒成像技术测量50例高危妊娠胎儿二、三尖瓣环处心肌运动速度( Ea,Aa,Sa 峰) 来反映左、右心室的心肌舒张及收缩功能.另外测定了与其年龄匹配的120例正常妊娠胎儿心脏的组织多普勒参数作为对照组.结果 (1)高危妊娠组及正常妊娠组胎儿二、三尖瓣环的运动速度( Ea,Aa )均与孕周呈正相关,随孕周的增长而增加;高危妊娠组及正常妊娠组胎儿二、三尖瓣环的运动速度(Sa)均与孕周无相关性.(2)高危妊娠组及正常妊娠组胎儿三尖瓣环的速度均大于相应二尖瓣环的运动速度(Ea、Aa、Sa峰).(3)高危妊娠组胎儿二、三尖瓣环的运动速度( Ea,Aa,Sa 峰) 均低于正常妊娠组.结论 高危妊娠组胎儿左、右心室心肌收缩及舒张功能均受到影响,组织多普勒技术可以评价高危妊娠胎儿心脏的收缩及舒张功能.     

多普勒超声观察正常11~14周胎儿心脏大血管的研究

目的 应用多普勒技术观察妊娠11+0～14+6周正常胎儿心脏大血管的血流动力学参数.方法 对230位正常妊娠孕妇在11+0～14+6周进行常规超声检查,同时观察胎儿心脏大血管.结果 主动脉血流速度高于主肺动脉和动脉导管,与孕周之间呈正相关,大动脉的射血时间与孕周之间呈正相关,而射血加速时间与孕周之间呈负相关;妊娠11～14周胎儿静脉导管显示率相对较低,而静脉导管的血流速度、搏动指数、阻力指数与孕周之间无相关性;至妊娠13周以后主动脉、主肺动脉、动脉导管的流速、射血时间和射血加速时间以及静脉导管的血流参数相对恒定.结论 妊娠13周以后可进行胎儿早期超声心动图检查,但胎儿心脏大血管的观察难度较大.胎儿心脏大血管的血流动力学表现可直接反映大血管本身状况,也可间接反应心脏的功能.当胎儿心脏结构或功能发生异常时,有可能引起大血管血流动力学的改变.     

组织多普勒技术对糖尿病妊娠胎儿心功能的评价

目的 通过组织多普勒技术测量胎儿二、三尖瓣环的运动速度来评价胎儿的心肌收缩与舒张功能，以此评估妊娠糖尿病胎儿心脏功能的损害程度。方法 妊娠糖尿病22例，正常对照组30例，使用组织多普勒测量胎儿心脏二尖瓣及三尖瓣环处的运动速度，并使用M型超声测量左右心的射血分数EF。结果 两组胎儿心肌舒张功能随孕周增长而增加，收缩功能与孕周无关。妊娠糖尿病胎儿心肌的舒张及收缩功能均比正常妊娠降低，射血分数高于正常。结论 组织多普勒技术是一项评价病理妊娠状态下胎心功能的新技术。     

E/Em评价中晚孕期正常胎儿心脏舒张功能的研究

目的 建立中晚孕期正常胎儿心脏舒张功能指标E/Em的参考值,与传统超声及组织多普勒成像技术(tissue Doppler image,TDI)评价心脏舒张功能指标进行综合分析,并探讨不同孕期该指标的演变规律.方法 327例孕18～42周正常胎儿选为研究对象,PWD测量房室瓣口血流E、A,TDI测量Em、Am、Sm,计算E/A、Em/Am、E/Em,对各组参数之间的差异及E/Em随孕周的演变规律分别进行分析.结果 E/Em与各参数均呈负相关;同一胎儿右心室E/Em小于左心室,其余右心室舒张功能参数均大于左心室;E/Em与孕周呈直线关系,随着孕周增加,E/Em呈递减趋势,并且晚孕组递减幅度较中孕组大.结论 E/Em与胎儿心室充盈压密切相关,能够可靠地反映心脏舒张功能,是一个简单、敏感、可靠的指标,建立正常中晚孕期胎儿E/Em的正常值范围,并研究其在不同孕期的演变规律,对于围产期胎儿心功能不全的准确评估具有重要的临床价值.     

二维斑点追踪技术评估超重及肥胖女性妊娠期胎儿心室收缩功能的研究

目的应用二维斑点追踪技术评价超重及肥胖女性妊娠期胎儿心室收缩功能。 方法选取空军军医大学唐都医院2019年6月至2020年3月单胎妊娠的孕妇80例,所有孕妇均于孕24周行常规胎儿超声心动图及二维斑点追踪成像检查。依据孕前体质量指数（BMI）将研究对象分为正常对照组30例、超重组27例和肥胖组23例。采用常规超声心动图及二维斑点追踪技术,对各组胎儿心脏结构、常规心室舒张及收缩功能指标、全心整体球形指数（GSI）以及左、右心室心内膜整体纵向应变（GLS）和右心室游离壁应变（FWSt）进行评价及比较分析。 结果肥胖组、超重组与正常对照组的胎儿左、右房室横径,心脏面积,心胸面积比及四腔心横径、长径,GSI比较,差异均无统计学意义（P均＞0.05）。各组胎儿二、三尖瓣口血流E/A值及瓣环运动速度e/a值差异均无统计学意义,肥胖组二、三尖瓣瓣环收缩期运动速度s较正常对照组及超重组均降低,差异均有统计学意义（P均＜0.05）。各组胎儿左心室射血分数,左、右心室面积变化率,二尖瓣环收缩期位移及三尖瓣环收缩期位移比较,差异均无统计学意义（P均＞0.05）。左、右心室GLS,及右心室FWSt在正常对照组、超重组、肥胖组均依次逐渐减低,组间差异均有统计学意义（P均＜0.05）。 结论超重女性妊娠可能会使胎儿心肌功能发生改变,左、右心室纵向应变各参数指标可以较好地反映超重及肥胖女性妊娠所引起的胎儿心肌收缩功能改变,有利于孕期随访观察及指导孕妇体重管理。     

超声心动图Tei指数评估前置胎盘胎儿心功能的应用价值

目的 探究超声心动图Tei指数在评估前置胎盘胎儿心功能中的应用价值及其与不良妊娠结局的关系。方法 选择产检孕妇140例,孕周均28～40周,分为前置胎盘组(前置胎盘70例)和对照组(健康孕妇70例),比较两组胎儿心脏超声检查参数和妊娠结局,前者包括左心室等容舒张时间(LV-IRT)、等容收缩时间(LV-ICT)、射血时间(LV-ET)、心肌做功指数(LV-Tei指数)及二、三尖瓣口E/A。结果 与对照组相比,前置胎盘组LV-Tei指数、LV-IRT显著增高(P<0.01);两组胎儿LV-ICT、LV-ET及二、三尖瓣口E/A无显著差异(P>0.05)。Pearson分析显示Tei指数与不良妊娠结局呈正相关(r=0.495,P<0.001),LV-Tei指数预测不良妊娠结局的受试者工作特征(ROC)曲线下面积为0.724(95%CI:0.640～0.808,P=0.002)。结论 前置胎盘孕妇胎儿的心功能降低,基于LV-Tei指数绘制的ROC曲线诊断不良妊娠结局的效能相对较高,可为早期监测宫内状况提供依据。     

超声心动图对胎儿脐绕颈心功能的研究

目的:研究胎儿脐带绕颈的心功能变化。方法:应用多普勒超声心动图测定61例正常胎儿(正常胎儿组)和52例脐绕颈胎儿(脐带绕颈组)心脏每搏输出量(SV=TI×Arca)、心输出量(CO)表示心脏收缩功能参数;舒张早期峰值流速(PFVe)、舒张晚期峰值流速(PFVa)、PFVe/PFVa(E/A)、平均流速(V)表示舒张功能的参数。结果:在正常胎儿组中左心室的SV、CO均小于右心室。二尖瓣的PFVe、PFVa、V均小于三尖瓣。脐绕颈组与正常胎儿组比较,左、右心室的SV、CO均增加;二、三尖瓣的PFVe增加,PFVa减低;E/A升高。结论:脐绕颈胎儿心脏的舒张功能改善,心输出量增加。     

Reference values for left and right ventricular systolic-to-diastolic duration ratio (SDR) found using both spectral and tissue Doppler of fetal heart between 20 and 36+6 weeks of gestation

Purpose

To establish reference values for the systolic-to-diastolic duration ratio (SDR) of the left ventricle (LV) using spectral Doppler, as well as for the SDR’ of the interventricular septum (SEP), LV, and right ventricles (RV) using tissue Doppler of the fetal heart.

Method

This prospective and cross-sectional study evaluated 374 low-risk singleton pregnancies from 20 to 36 + 6 weeks of gestation. The ventricular filling time (FT) was obtained from LV inflow using spectral Doppler. Tissue Doppler was used to assess the FT of each ventricle by placing the cursor at the atrioventricular junction marked by the mitral and tricuspid valves, respectively. SDR was calculated as the sum of the isovolumic contraction time (ICT) and the ejection time (ET) divided by the sum of the isovolumic relaxation time (IRT) and the ventricular FT. We used regression analysis to obtain the best-fit model polynomial equation for the parameters. The concordance correlation coefficient (CCC) was used to assess intra- and inter-observer reproducibility.

Results

SDR and SDR’ LV showed a progressive decrease with gestational age (GA); the SDR’ RV and SDR’ SEP did not show a significant decrease with advancing GA. The SDR LV (r = 0.29, p < 0.0001), SDR’ RV (r = 0.21, p < 0.0001), SDR’ LV (r = 0.20, p = 0.0001), and SDR’ SEP (r = 0.25, p < 0.0001) showed a significant weak positive correlation with fetal heart rate. The inter-observer SDR’ SEP measurements demonstrated poor reproducibility (CCC: 0.50), whereas intra-observer SRD LV measurements demonstrated moderate reproducibility (CCC: 0.78).

Conclusions

Reference values for SDR SEP, LV, and RV using spectral and tissue Doppler of fetal heart were established between 20 and 36+6 weeks of gestation.

     

Abnormal cardiac function in fetuses with increased nuchal translucency.

OBJECTIVE: To evaluate cardiac function in structurally and chromosomally normal fetuses with increased nuchal translucency (NT). METHODS: Forty-two structurally and chromosomally normal fetuses with increased NT at 11-14 weeks of gestation underwent fetal echocardiographic examination at 20-23 weeks. Fifty fetuses with normal NT values were considered as controls. Pulmonary and aortic peak velocity and time to peak velocities were measured as indices of ventricular systolic function. The ratios between the E-wave and A-wave (E/A) and the ratios between the E-wave and time velocity integral (E/TVI) at the level of both atrioventricular valves were evaluated as indices of ventricular diastolic function. RESULTS: In fetuses with increased NT the E/A ratios were significantly decreased when compared to control fetuses at the level of both the mitral (0.52 +/- 0.09 vs. 0.60 +/- 0.10, P = 0.0002) and tricuspid (0.51 +/- 0.09 vs. 0.61 +/- 0.09, P < 0.0001) valves. Similar results were found for the E/TVI ratios (mitral valve 4.79 +/- 1.03 vs. 5.63 +/- 1.23, P = 0.0007 and tricuspid valve 4.40 +/- 0.88 vs. 5.19 +/- 0.82, P < 0.0001). No significant relationship was found between the degree of NT and the abnormalities in Doppler indices. There were no significant differences in Doppler systolic indices. CONCLUSION: Structurally and chromosomally normal fetuses with increased NT have low E/A and E/TVI ratios at 20-23 weeks of gestation. These findings might indicate cardiac diastolic dysfunction.     

Cardiac resynchronization therapy acutely improves diastolic function.

BACKGROUND: Invasive studies have shown that cardiac resynchronization therapy (CRT) acutely improves left ventricular (LV) systolic performance and lowers filling pressures in a majority of patients with medically-refractory severe heart failure. Measurements included LV volume, ejection fraction, PWD early (E-wave) and atrial (A-wave) velocities, diastolic filling time (DFT), and DTI early diastolic mitral annular velocity (Em) at the lateral and septal annulus; PWD mitral E-wave/Em and E/FP were calculated to estimate LV filling pressures. RESULTS: Immediately after CRT, LV volumes decreased and LVEF increased significantly. PWD mitral E-wave velocity decreased and E-wave duration and DFT increased significantly; mitral E/FP ratio also decreased significantly, consistent with a decrease in LV filling pressure. Patients with a pre-CRT mitral E/A ratio >1 (n = 20), demonstrated improvements in LV diastolic filling and lower filling pressures whereas those with an E/A ratio < or =1 (n = 21) did not show significant changes in diastolic indices. CONCLUSIONS: The acute effects of CRT include echocardiographic evidence of reduced LV volumes and increased LVEF with improved diastolic filling and lower filling pressures; LV relaxation is not significantly altered. The benefits in diastolic function are dependent on the PWD-determined LV filling characteristics prior to CRT.     

Cardiac function in fetuses with intracardiac echogenic foci.

OBJECTIVE: To evaluate cardiac dimensions and function in euploid fetuses with intracardiac echogenic foci. STUDY DESIGN: Forty-eight fetuses with a single cardiac echogenic focus situated in the left ventricle had echocardiography performed at 22-24 weeks of gestation. Fifty normal fetuses at 22-24 weeks' gestation served as controls. Two-dimensional and M-mode directed fetal echocardiography were used to exclude cardiac anomalies and measure right and left ventricular free walls and interventricular septal thickness and ventricular systolic and diastolic dimensions. Cardiac size was expressed as a ratio of ventricular wall thickness/biparietal diameter, and cardiac function was expressed as ventricular shortening fraction. Doppler fetal echocardiography measurements included pulmonary and aortic maximum systolic velocities and time to peak velocities as indices of ventricular systolic function, and the ratio between early ventricular filling (E-wave) and active atrial filling (A-wave) peak velocities at the level of the atrioventricular valves as an index of ventricular diastolic function. RESULTS: Early ventricular filling/active atrial filling peak velocity ratios were significantly lower in fetuses with intracardiac echogenic foci than in control fetuses. In the mitral valve the ratio was 0.37 +/- 0.14 (0.039) (mean +/- SD (95% confidence interval for difference between the means)) vs. 0.59 +/- 0.19 (0.052) and in the tricuspid valve it was 0.42 +/- 0.16 (0.045) vs. 0.62 +/- 0.21 (0.058). No significant differences were found in cardiac dimensions, ventricular shortening fraction and Doppler systolic indices. CONCLUSION: Euploid fetuses with intracardiac echogenic foci show low E/A ratio values in midtrimester echocardiography. This finding might indicate cardiac diastolic dysfunction.     

多普勒超声评价慢性二尖瓣返流左室舒张功能

用脉冲多普勒超声技术对１８例慢性二尖瓣返流（ＣＭＲ）患者和２１例正常人进行二尖瓣舒张期血流频谱定量研究。结果表明，ＣＭＲ出现的假性正常的二尖瓣血流频谱，掩盖了左室舒张功能减退，实际为左室松驰功能障碍及顺应性降低所致。ＣＭＲ组的Ｅ波压差（Ｅ－ＰＧ）、Ａ波压差（Ａ－ＰＧ）、等容舒张时间（ＩＶＲＴ）、Ｅ波减速时间（Ｅ－ＤＴ）及左室充盈时间．（ＬＶＦ）等与正常对照组比较有显著性差异（Ｐ＜０．０１），是ＣＭＲ情况下反映左室舒张功能减退的综合评价指标。     

不同孕周胎儿心脏结构及其心功能的相关参数的分析

[目的]探讨不同孕周胎儿心脏结构及其心功能的相关参数.[方法]应用彩色多普勒超声心动图检测不同孕周孕妇216例,比较不同孕周胎儿心腔径线、瓣膜口峰值血流速度、射血分数和Tei指数.[结果]胎儿时期心脏各腔室大小随着孕周的增长而增大,右室大于左室,结构上右室占优势;各瓣口峰值血流速度随胎龄增加而升高,二尖瓣小于三尖瓣,主...     

Differentiation of abnormal relaxation pattern with aging from abnormal relaxation pattern with coronary artery disease in transmitral flow with the use of tissue Doppler imaging of the mitral annulus.

An abnormal relaxation pattern in transmitral flow velocity waveforms has been observed in older healthy subjects as well as in patients with heart disease. Accordingly, we investigated whether the hemodynamic differences between patients with coronary artery disease (CAD) with an abnormal relaxation pattern in transmitral flow (ratio of E-wave to A-wave velocities < 1.0) and healthy older subjects with an abnormal relaxation pattern can be distinguished with the use of mitral annular velocity (MAV) during early diastole. We measured MAV in the longitudinal direction of the heart during early diastole by M-mode color tissue Doppler imaging in 24 patients with atypical chest pain (defined as healthy subjects in this study) and 70 patients with CAD who underwent cardiac catheterization. In all patients a time constant of left ventricular pressure decay (tau) and the left ventricular (LV) end-systolic volume index were also measured. Twenty-one healthy subjects and 59 patients with CAD had an abnormal relaxation pattern in their transmitral flow. The age, heart rate, mean blood pressure, and ratio of E-wave to A-wave velocities were not different between the two groups. However, the tau was longer and the LV end-systolic volume index was greater in patients who had an abnormal relaxation pattern with CAD than in healthy subjects with an abnormal relaxation pattern. The MAV during early diastole was lower in the former than in the latter (5.8 +/- 1. 9 vs 9.8 +/- 1.9 cm/s, P <.001). Mitral annular velocity during early diastole by M-mode color tissue Doppler imaging can detect the differences in LV relaxation and LV systolic performance between the abnormal relaxation pattern with CAD and the physiologically abnormal relaxation pattern with aging, providing further information regarding the meaning of an LV abnormal relaxation pattern.     

Valvuloplasty of fetal pulmonary atresia with intact ventricular septum and hypoplastic right heart: Mid-term follow-up results

ObjectiveThis study aimed to analyze and evaluate the results of mid-term follow-up after fetal pulmonary valvuloplasty (FPV) in fetuses with pulmonary atresia with intact ventricular septum (PA/IVS).MethodsFrom August 31, 2018, to May 31, 2019, seven fetuses with PA/IVS and hypoplastic right heart were included in this study. All underwent echocardiography by the same specialist and were operated on by the same team. Intervention and echocardiography data were collected, and changes in the associated indices noted during follow-up were analyzed.ResultsAll seven fetuses successfully underwent FPV. The median gestational age at FPV was 27.54 weeks. The average FPV procedural time was 6 ?min. Persistent bradycardia requiring treatment occurred in 4/7 procedures. Finally, five pregnancies were successfully delivered, and the other two were aborted. Compared to data before fetal cardiac interventions (FCI), tricuspid valve annulus diameter/mitral valve annulus diameter (TV/MV) and right ventricle diameter/left ventricle diameter (RV/LV) of all fetuses had progressively improved. The maximum tricuspid regurgitation velocity decreased from 4.60 ?m/s to 3.64 ?m/s. The average follow-up time was 30.40 ?± ?2.05 months. During the follow-up period, the diameter of the tricuspid valve ring in five children continued to improve, and the development rate of the tricuspid valve was relatively obvious from 6 months to 1 year after birth. However, the development of the right ventricle after birth was relatively slow. It was discovered that there were individual variations in the development of the right ventricle during follow-up.ConclusionThe findings support the potential for the development of the right ventricle and tricuspid valve in fetuses with PA/IVS who underwent FCI. Development of the right ventricle and tricuspid valve does not occur synchronously during pregnancy. The right ventricle develops rapidly in utero, but the development of tricuspid valve is more apparent after birth than in utero.     

Systemic assessment of fetal hemodynamics by Doppler ultrasound

The aim of our study was to investigate the parameters of fetal circulation of normal pregnancies and their relationship to fetal cardiac output. We performed a cross-sectional study of 315 normal singleton pregnancies between 20 and 40 weeks' gestation without fetal chromosomal or structural malformations. After follow-up to delivery, 212 patients who fit all the criteria were enrolled for final analysis. Blood flow velocity waveforms were obtained from the tricuspid and mitral ventricular inflow, ascending aorta (AAO), pulmonary artery (PA), middle cerebral artery (MCA), renal artery (RA), umbilical artery (UA), descending aorta (DAO), inferior vena cava (IVC) and ductus venosus (DV) using duplex (real-time Doppler) ultrasound (US) scanner. The peak velocity of DV, AAO, PA and MCA were also obtained. At the intracardiac level, the ratio of peak flow velocity of E wave to peak flow velocity of A wave (E:A ratio) of mitral valve (MV) increased more rapidly than tricuspid valve (TV) E:A ratio. For the great vessels, aortic peak velocity remained higher than the pulmonary peak velocity with advancing gestation. The cardiac output closely correlated to the cardiac compliance and flow resistance indices at arterial and venous level. The acceleration time in the fetal arteries increased with advancing gestation in AAO, PA, MCA and DAO, but it decreased in RA and kept constant in UA. In addition, the acceleration time of UA was unrelated to cardiac output. The changes of the fetal intracardiac, arterial and venous impedances were remarkable through the gestation and related to cardiac output. Fetal cardiac output correlated well with the changes of arterial resistance, except with the DAO. The ventricular compliance increased with advancing gestation, especially in the left side, and was highly related to the change of cardiac output. The acceleration time in major arteries positively correlated with the gestational age and cardiac output, except in UA and RA; this indicates the difference of the changes of mean arterial pressure in uteroplacental circulation, fetal organs and great vessels. In conclusion, the fetal cardiac output correlated well with the ventricular compliance and was influenced by both hemodynamic changes in peripheral resistance and mean arterial pressure.