胎儿静脉导管超声检查在预测宫内生长受限胎儿出生结局中的应用价值

目的探讨胎儿静脉导管超声检查在预测宫内生长受限胎儿不良出生结局中的应用价值。方法选取我院确诊存在宫内生长受限胎儿的孕妇53例,依据新生儿出生不同结局分为正常组23例、轻微异常组15例和明显异常组15例。检测比较各组胎儿静脉导管多普勒血流参数变化情况。结果胎儿静脉导管的心室收缩期峰值流速/最大心房期回流速度(DVS/A)、静脉导管的阻力指数(DVRI)及静脉导管血流量/脐静脉血流量(QDV/QUV)均可以对FGR胎儿的明显异常出生结局作出预测,其中DVS/A曲线下面积最大,为91%,其次为DVRI,曲线下面积为90%,QDV/QUV曲线下面积为74%。结论 DVS/A、DVRI及QDV/QUV均可以作为预测宫内生长受限胎儿明显异常出生结局的指标,其中DVS/A、DVRI预测价值较高。     

Longitudinal reference ranges for ductus venosus flow velocities and waveform indices.

OBJECTIVES: Serial Doppler measurements of the ductus venosus are used increasingly for monitoring fetuses at risk of hemodynamic compromise, but existing reference ranges are based on cross-sectional studies and thus are less suitable for comparison with serial measurements. We aimed to establish longitudinal reference ranges for ductus venosus flow velocities and waveform indices and to provide the necessary terms for calculating conditional reference ranges for serial measurements. METHODS: This was a longitudinal study of 160 low-risk pregnancies. Pulsed Doppler ultrasound was used to record ductus venosus blood flow velocities at 4-week intervals from 20-22 weeks of gestation onwards. RESULTS: With a success rate of 93%, 547 measurements (four or five in each fetus) were used to establish reference ranges. The time-averaged maximum velocity was 50 cm/s at 21 weeks of gestation, increased to 60 cm/s at 32 weeks, and remained so until term. Similarly, the peak systolic velocity increased from 59 cm/s at 21 weeks to 71 cm/s at 31 weeks and remained so until term. The end-diastolic velocity showed a continuous increase from 31 cm/s at 21 weeks to 43 cm/s at 40 weeks. The pulsatility index for veins decreased from 0.57 at 21 weeks to 0.44 at 40 weeks. When conditioned by a previous measurement, the reference ranges for the next observation became narrower and commonly shifted compared with those of the entire population. CONCLUSION: The new longitudinal reference ranges presented here reflect the development of the ductus venosus flow velocities and velocity indices and are thus appropriate for serial measurements, particularly if conditional terms are included.     

Effect of fetal gender on first-trimester ductus venosus blood flow.

OBJECTIVES: Recent reports have suggested that nuchal translucency (NT) measurements in the first trimester may be influenced by fetal gender. Since both NT and central venous blood flow are considered to be related to fetal cardiac function, we investigated gender-related differences in first-trimester ductus venosus Doppler indices. METHODS: A total of 73 male and 79 female normal fetuses at 10-14 weeks of gestation were included in the study. The pulsatility index for veins (PIV), peak velocity during ventricular systole (S-wave), time-averaged maximum velocity (TAMV) and A-wave velocity (A-wave) were recorded in each case and converted to the corresponding Z-scores. RESULTS: The mean Z-score values of PIV, S-wave and TAMV were significantly lower in male fetuses compared to female fetuses (P < 0.01 for all three indices). By contrast, A-wave velocities were not different in the two groups. The correlation between S-wave velocity and TAMV was significant in both male (P < 0.001) and female (P < 0.001) fetuses, while PIV did not appear to be related to TAMV either in males (P = 0.90) or in females (P = 0.49). A-wave velocity had a significant negative correlation with PIV in both groups. Finally, PIV was significantly correlated with S-wave velocity in female fetuses (P < 0.01) but not in males (P = 0.14). CONCLUSION: These findings suggest that early cardiovascular development may be different in male and female fetuses.     

Middle cerebral artery peak systolic and ductus venosus velocity waveforms in the hydropic fetus.

OBJECTIVE: The purpose of this study was to assess whether Doppler assessment of the middle cerebral artery (MCA) peak systolic velocity (PSV) and ductus venosus (DV) velocity waveforms during sonography of hydropic fetuses may specify the cause of fetal hydrops. METHODS: A level II sonographic examination was performed in 16 hydropic fetuses, and the MCA PSV and DV velocity waveforms were assessed. The MCA PSV values divided hydropic fetuses into anemic (group 1) and nonanemic (group 2) fetuses. In group 2 fetuses, the DV was defined as normal or abnormal. Sonographic examination and Doppler assessment of these vessels specified the cause of hydrops and indicated the use of specific investigations for diagnosing the etiology of fetal hydrops. RESULTS: Seven of 16 fetuses had MCA PSV values greater than 1.50 multiples of the median (group 1). Nine of 16 fetuses had normal MCA PSV values (group 2); among them, 7 of 9 had either absent or reversed flow in the DV, and 2 had a normal DV. In group 1, the cause of fetal anemia was investigated by maternal serum tests, and 5 cordocentesis procedures were performed. In group 2, 7 of 9 fetuses had reversed flow in the DV, which suggested a cardiac abnormality confirmed by echocardiography. Five cordocentesis procedures were performed for fetal karyotype, and in 2 fetuses, the cause of hydrops was idiopathic. CONCLUSIONS: Our data suggest that assessment of the MCA PSV and DV velocity waveforms in the hydropic fetus may further our knowledge of the etiology of hydrops and may indicate which investigations among the many available should be used for diagnosing the cause of fetal hydrops.     

早孕期胎儿静脉导管频谱波型分析

目的探讨早孕期不同类型胎儿静脉导管频谱波型与胎儿生长发育及预后之间的关系。方法165例头臀长（CRL）在25-80mm之间的高危胎儿接受了经腹壁早孕期超声检查及绒毛活检。根据胎儿静脉导管血流不同波型将频谱形态分为三型：Ⅰ型：在整个心动周期内无反向血流;Ⅱ型：在心房收缩期的起始段出现很短时间内的反向血流信号,随后的大部分心房收缩期内为正向血流信号;Ⅲ型：在整个心房收缩期内为持续反向血流。所有本组胎儿进行了产前染色体核型分析、基因学及酶学检查,并随访至生后。结果在本组病例中,只有2例胎儿静脉导管频谱波型为Ⅲ型,绒毛检查结果证实其中一例为21-三体,另一例为黏多糖储积症。26例胎儿经基因学诊断为遗传性疾病,2例胎儿宫内死亡。在其余135例正常发育胎儿组中,95例（70.4%）胎儿静脉导管频谱为Ⅰ型,40例（29.6%）胎儿频谱为Ⅱ型。按胎儿头臀长分为5组（≤39mm,40-49mm,50-59mm,60-69mm,≥70mm）后,Ⅰ型/Ⅱ型胎儿例数分别为24/16、31/8、15/13、11/2、14/1。应用非参数检验的统计学方法分析,结果显示Ⅰ型及Ⅱ型频谱波型的出现频率与胎儿头臀长分组密切相关（P=0.015）,绝大多数的Ⅱ型静脉导管频谱出现在头臀长小于60mm的胎儿组中。结论通过本组正常胎儿的研究显示,早孕期胎儿静脉导管频谱波型中心房收缩早期出现的很短的反向血流信号应被视为一种“正常变异”现象,而非一种异常的静脉导管频谱类型,特别是在胎儿头臀长小于60mm时。     

Color Doppler study of the venous circulation in the fetal brain and hemodynamic study of the cerebral transverse sinus.

OBJECTIVES: To describe the venous circulation in the fetal brain; to describe the normal blood flow velocity waveform in the transverse sinus and to establish normal reference ranges for the second half of gestation. POPULATION: A total of 126 pregnant women with uncomplicated pregnancies at 20-42 weeks of gestation. METHODS: A combination of color-coded Doppler and two-dimensional real-time ultrasound was used to identify the main venous systems in the fetal brain. Blood flow velocity waveforms of the transverse sinus were obtained from a transverse plane of the head at the level of the cerebellum. RESULTS: A waveform could be obtained in the cerebral transverse sinus in 98% of the cases. The waveform obtained was triphasic with a forward systolic component, a forward early diastolic component and a lower forward component in late diastole. Reverse flow during atrial contraction was seen before 28 weeks and the diastolic flow increased with gestation thereafter. Pulsatility and resistance indices decreased and flow velocities increased in the transverse sinus throughout gestation. CONCLUSION: The venous circulation of the fetal brain can be identified by color Doppler. The gestational age-related decrease in resistance and increase in flow velocities suggest that hemodynamic studies of the cerebral transverse sinus might have clinical implications in studying compromised fetuses.     

Normal values of fetal ductus venosus blood flow waveforms during the first stage of labor.

OBJECTIVE: To present normal values of fetal ductus venosus blood flow waveforms during the first stage of labor during and between contractions. MATERIALS AND METHODS: Seventy-eight women between the 37th and 41st weeks of gestation were included in the study. At distinct stages of cervical dilation, blood flow velocity waveforms of the fetal ductus venosus during and between contractions were visualized in fetuses with a normal non-stress test. The pulsatility index for veins, peak velocity index for veins and fetal heart rate were calculated off-line. The means +/- standard deviations (SD) during and between contractions were compared using the Wilcoxon test. RESULTS: Ductus venosus blood flow velocity waveforms were visualized during 331 contractions and 375 episodes of uterine quiescence in 74 of 78 fetuses (95%) during normal labor. The mean +/- standard deviation values of pulsatility and peak velocity indices for veins during contractions were 1.66 +/- 0.85 (median: 1.56, range: 0.29-4.69) and 1.46 +/- 0.65 (median: 1.34, range: 0.26-3.13), respectively. Between contractions the values were 0.48 +/- 0.19 (median: 0.46, range: 0.14-1.00) for the pulsatility index and 0.44 +/- 0.18 (median: 0.42, range: 0.14-1.00) for the peak velocity index for veins. These differences during and between contractions were highly significant (P-value < 0.0001), whereas the fetal heart rate showed no significant differences. CONCLUSION: There are significant differences in fetal ductus venosus blood flow waveforms during and between labor contractions. Further studies should evaluate whether these normal values of the fetal ductus venosus are beneficial for risk evaluation in fetuses with an abnormal non-stress test and/or intrauterine growth restriction.     

Fetal ductus venosus, middle cerebral artery and umbilical artery flow responses to uterine contractions in growth-restricted human pregnancies.

OBJECTIVE: To explore fetal ductus venosus (DV) flow velocity changes relative to umbilical artery (UA) blood flow and brain-sparing flow (BSF) during uterine contractions. METHODS: Forty-five term fetuses suspected of having growth restriction were exposed to an oxytocin challenge test (OCT) with simultaneous Doppler velocimetry in the UA, middle cerebral artery (MCA) and DV. Basal BSF was defined as a MCA-to-UA pulsatility index (PI) ratio of < 1.08, and de novo BSF as a decrease in MCA-PI of > or = 1 SD (equivalent to a value of 0.24 units) during the OCT. RESULTS: Basal DV flow velocities were lower in the BSF group (n = 7) than they were in the non-BSF group (n = 38). During the OCT, DV flow velocity parameters changed in neither group but MCA-PI decreased in the non-BSF group. A crude de novo BSF was not associated with DV flow velocity changes, but when UA-PI changes were considered, a serial relationship was found between decreased UA-PI, increased DV flow velocity, and decreased MCA-PI. When UA-PI increased, the MCA-PI still decreased (though not significantly) but DV flow velocity parameters remained unchanged. CONCLUSIONS: Established fetal BSF is associated with low DV flow velocities, but in an acute sequence there might be two contrasting courses along which BSF develops: one with an increase and one with a decrease in the UA vascular flow resistance. In the former situation the DV flow velocity increases, while in the latter situation the role of the DV in the acute redistribution of fetal blood flow is unclear.     

Intrauterine growth restriction and fetal body composition.

OBJECTIVE: To assess the differences in fetal body compartments between fetuses with normal growth and those with reduced intrauterine growth, during the third trimester, through ultrasonographic determination of subcutaneous tissue thickness (SCTT). METHODS: Twenty-eight patients were enrolled into this case control study carried out at 30-31 weeks' gestation. Two study groups were matched for maternal age and pregestational body mass index: controls (n = 14) and intrauterine growth-restricted (IUGR) fetuses (n = 14). Routine ultrasound-derived biometric parameters (head circumference, abdominal circumference, femur length and humerus length) were measured. Additionally, the mid-arm fat mass and lean mass (MAFM and MALM), the mid-thigh fat mass and lean mass (MTFM and MTLM), the abdominal fat mass (AFM) and the subscapular fat mass (SSFM) were measured. The Mann-Whitney U-test and Student's t-test were used to compare the two groups. RESULTS: The abdominal circumference and the humerus were significantly smaller in IUGR fetuses than in controls. Most of the SCTT values were different in the two groups. The SSFM (3.6 +/- 1.1 vs. 2.6 +/- 0.7 mm; P = 0.011), the AFM (5.1 +/- 0.7 vs. 4 +/- 1 mm; P = 0.01), the MAFM (3.5 +/- 0.9 vs. 2.2 +/- 0.8 cm2; P < 0.01) and MALM (2.1 +/- 0.4 vs. 1.7 +/- 0.5 cm2; P = 0.029) were all significantly greater in fetuses with normal development compared to those with growth restriction. CONCLUSIONS: During the third trimester, SCTT (with the exception of MTFM and MTLM) is reduced in fetuses with IUGR. Furthermore, MALM is lower in growth-restricted fetuses, confirming that the parameters measured in this study are affected in IUGR fetuses. Our findings indicate that specific changes in fetal body compartments occur as a result of chronic metabolic impairment.     

The sequence of changes in Doppler and biophysical parameters as severe fetal growth restriction worsens.

OBJECTIVE: To test the hypothesis that hemodynamic changes depicted by Doppler precede deteriorating biophysical profile score in severe intrauterine growth restriction. METHODS: Intrauterine growth-restricted fetuses with elevated umbilical artery Doppler pulsatility index (PI) > 2 standard deviations above mean for gestational age and birth weight < 10th centile for gestational age were examined longitudinally. Fetal well-being was assessed serially with five-component biophysical profile scoring (tone, movement, breathing, amniotic fluid volume and non-stress test) and concurrent Doppler examination of the umbilical artery, middle cerebral artery and ductus venosus, inferior vena cava and free umbilical vein. For fetuses with a final biophysical profile score < 6/10, progression of biophysical profile scoring, arterial PI and venous peak velocity indices were analyzed longitudinally. Gestational age effect was removed by converting indices to Z-scores (deviation from gestational age mean, in standard deviations). RESULTS: Forty-four of 236 intrauterine growth-restricted fetuses (18.6%) required delivery for abnormal biophysical profile scoring. The median gestational age at entry was 25 weeks and 1 day and at delivery was 29 weeks and 6 days. The median interval between examinations was 1.5 days and the majority had daily testing in the week prior to delivery. Between first examination and delivery, significant deterioration was observed for Doppler criteria (chi-square, P < 0.001) and biophysical parameters (Fisher's exact, P = 0.02) predominantly confined to the week prior to delivery/stillbirth. Doppler variables changed first. In 42 fetuses (95.5%), one or more vascular beds deteriorated, accelerating especially in the umbilical artery and ductus venosus at a median of 4 days before biophysical profile scoring deteriorated. Two to 3 days before delivery, fetal breathing movement began to decline. The next day, amniotic fluid volume began to drop. Composite biophysical profile score dropped abruptly on the day of delivery, with loss of fetal movement and tone. Three principal patterns of Doppler deterioration were observed: (i) worsening umbilical artery PI, advent of brain sparing and venous deterioration (n = 32, 72.7%); (ii) abnormal precordial venous flows, advent of brain sparing (n = 6, 13.6%); and (iii) abnormal ductus venosus only (n = 4, 9.1%). In the majority (31, 70.5%), Doppler deterioration was complete 24 h before biophysical profile score decline. In the remainder (11, 25%), Doppler deterioration and biophysical profile score < 6/10 were simultaneous. CONCLUSION: In the majority of severely intrauterine growth-restricted fetuses, sequential deterioration of arterial and venous flows precedes biophysical profile score deterioration. Adding serial Doppler evaluation of the umbilical artery, middle cerebral artery and ductus venosus to intrauterine growth restriction surveillance will enhance the performance of the biophysical score in the detection of fetal compromise and therefore optimizing the timing of intervention.     

静脉导管的多普勒血流流速曲线在筛选胎儿先天性心脏病中的临床意义

目的：探讨静脉导管的血流流速曲线在筛选和协助早期诊断胎儿先天性心脏病中的临床意义。方法：应用彩色多普勒超声诊断系统检测240例14－41孕周的正常胎儿和20例先天性心脏病胎儿的静脉导管血流流速曲线，并计算静脉导管血流阻力指数、搏动指数及心室收缩期峰值速度与心房收缩期最大流速比值。结果：①正常胎儿静脉导管的血流流速曲线呈特殊的波形：心室收缩期波峰S、心室舒张期波峰D和心房缩期波谷A，前向血流持续整个心动周期；②20例先天性心脏病胎儿中8例静脉导管的A波出现反转，9例A波降低或缺失，3例无明显变化。先天性心脏病胎儿组静脉导管血流指数较胎龄相匹配的正常胎儿组增高，两组比较差异有显著性意义（P＜0．05）。结论：彩色多普勒超声检测胎儿静脉导管的血流流速曲线可筛选或协助早期诊断胎儿先天性心脏病。     

胎儿静脉导管及颈项透明层厚度的超声检测在先天性心脏畸形筛查中的价值

目的 探讨胎儿静脉导管多普勒血流频谱异常及颈项透明层（NT）增厚在早期胎儿先天性心脏畸形（CHD）筛查中的临床应用价值.方法 对3562例孕11~14周的孕妇行常规产前检查,进行胎儿静脉导管多普勒血流频谱和NT检测,对静脉导管血流频谱异常或NT增厚胎儿于孕18~20周行超声心动图检查以确诊或除外CHD,对静脉导管血流频谱和NT正常的胎儿于20~24周行胎儿常规系统筛查,对可疑胎儿心脏异常者再行胎儿超声心动图检查.所有活产儿于出生后1周内进行超声心动图检查,对引产胎儿进行尸检.结果 ①3562例胎儿中静脉导管多普勒血流频谱异常胎儿CHD的发生率明显高于静脉导管多普勒血流频谱正常的胎儿（P ＜ 0.01）,其敏感性、特异性及阳性预测值分别为55.22%、96.97%和25.87%;②NT增厚的胎儿CHD发生率明显高于NT正常胎儿（P ＜ 0.01）,其敏感性、特异性及阳性预测值分别为49.25%、98.03%及32.35%;③静脉导管多普勒血流频谱异常和NT增厚的胎儿CHD发生率明显高于静脉导管多普勒血流频谱及NT均正常的胎儿（P ＜ 0.01）,其敏感性、特异性及阳性预测值分别为43.28%、99.46%和60.42%.结论 胎儿静脉导管多普勒血流频谱异常和NT增厚可作为CHD的早期筛查指标.     

Polyhydramnios and fetal intrauterine growth restriction: ominous combination.

The purpose of this study was to evaluate the significance of polyhydramnios combined with intrauterine growth restriction. During a 6 year period, 39 fetuses were identified by prenatal sonography as having both polyhydramnios and intrauterine growth restriction. Polyhydramnios was defined as a four-quadrant amniotic fluid index of 24 or greater (mean 30.5, range 24 to 40). Intrauterine growth restriction was defined as estimated fetal weight less than the tenth percentile (Hadlock standards). The mean birth weight was 2213 g. Major anomalies were present postnatally in 92% (36 of 39) of fetuses. Among nine fetuses without sonographically detectable anomalies prenatally, six (67%) proved to have one or more anomalies at birth. Chromosome abnormalities were present in 38% (15 cases) including 10 fetuses with trisomy 18 and one with trisomy 13. The overall mortality rate was 59%. The combination of polyhydramnios and intrauterine growth restriction is ominous. The majority of fetuses have major anomalies or chromosome abnormalities, or both, even when other sonographic abnormalities are absent. Chromosome analysis and detailed fetal evaluation should be offered when polyhydramnios and intrauterine growth restriction are identified prenatally.     

Fetal transverse cerebellar diameter measurements in normal and reduced fetal growth.

OBJECTIVES: To establish the increase in fetal transverse cerebellar diameter (TCD) relative to gestational age during normal and restricted fetal growth; to determine the significance of TCD and TCD/AC relationship in predicting fetal outcome as expressed by perinatal mortality. DESIGN: A retrospective cross-sectional study. SUBJECTS: Three hundred and sixty normally developing fetuses between 17 and 34 weeks of gestation and 73 growth-restricted fetuses between 24 and 34 weeks of gestation. METHODS: Ultrasonographic measurements included head circumference (mm), abdominal circumference (mm) and transverse cerebellar diameter (mm). A gestational age-related normal reference chart was produced for TCD. RESULTS: Statistically significant relationships between transverse cerebellar diameter and gestational age, abdominal circumference and head circumference were found. The normal fetal TCD exhibited a more than twofold increase in size during the second half of pregnancy. Twenty-six per cent of the small-for-gestational age (SGA) fetuses displayed a reduced TCD and 82% of the SGA fetuses demonstrated raised TCD/AC values. No statistically significant difference in perinatal mortality or birth weight was found between the subsets of growth-restricted fetuses with reduced or normal TCD; or between the subsets with normal or raised TCD/AC values. CONCLUSIONS: In the normally developing fetus the TCD increases with advancing gestational age. Increased TCD/AC values are suspicious of fetal growth restriction. The perinatal mortality in growth-restricted fetuses with a small cerebellum is increased twofold over that of other fetuses.     

Customized fetal weight limits for antenatal detection of fetal growth restriction.

OBJECTIVE: To define cut-off limits for individually adjustable fetal weight standards for the detection of intrauterine growth restriction. DESIGN: Retrospective study, with the outcome measures small-for-gestational age (SGA) birth weight, operative delivery for fetal distress, umbilical artery pH < 7.15, and admission to the neonatal intensive care unit. SUBJECTS AND METHODS: Two hundred and fifteen women considered to be at increased risk of uteroplacental insufficiency were recruited to a study of serial ultrasound scans. Fetal weights were derived using standard formulae and, retrospectively, weight percentiles were calculated after individual adjustment for maternal height, weight in early pregnancy, ethnic group, parity and fetal sex. INTRODUCTION: One or more antenatal scans indicative of fetal weight below the 10th customized percentile were predictive for a SGA neonate at birth (P < 0.001), operative delivery for fetal distress (P < 0.01) and admission to neonatal intensive care (P < 0.01) but not for a low umbilical artery pH (P = 0.6). Receiver-operator curves showed the optimal customized fetal weight percentile limit for predicting an SGA neonate to be the 18th percentile (sensitivity 83%, specificity 79%, positive predictive value 63% and negative predictive value 92%). For the prediction of operative delivery for fetal distress and admission to neonatal intensive care, the optional customized cut-off value was the 8th percentile. CONCLUSIONS: The assessment of fetal weight using ultrasound and an individually-adjusted standard is predictive of growth restriction and perinatal events associated with hypoxia or diminished reserve. The optimal cut-off value for predicting operative delivery for fetal distress or admission to the neonatal intensive care unit suggests that the 10th customized percentile is a good limit for clinical use.     

Imaging of the ductus venosus in neonates: from patency to closure.

OBJECTIVE: To familiarize the radiologist with the variable sonographic appearance of the involuting ductus venosus in neonates. METHODS: Five sick neonates ranging in age from 24 to 42 weeks had abdominal sonographic examinations to check for intra-abdominal diseases. RESULTS: Doppler sonography showed a patent ductus venosus in 3 neonates and a ductus venosus with thrombosis in 2 neonates. The ductus venosus was identified in the liver between the left portal vein and the inferior vena cava. In 2 patients, follow-up sonography showed that the ductus venosus progressively had thrombosis and then disappeared. CONCLUSIONS: The ductus venosus in a neonate has a variable sonographic appearance depending on its stage of involution. Its detection in a sick neonate can lead to inadvertent diagnosis of a hepatic varix, an abscess, or a tumor.     

Intraobserver and interobserver variability of transabdominal Doppler velocimetry measurements of the fetal ductus venosus between 10 and 14 weeks of gestation.

OBJECTIVE: To assess the intraobserver repeatability and interobserver reproducibility of transabdominal Doppler ultrasound measurements of ductus venosus blood flow in fetuses between 10 and 14 weeks of gestation. DESIGN: A prospective study with the following end-points: coefficient of variation, intraclass correlation coefficients within and between observers, repeatability coefficient and Cohen's kappa coefficient. SUBJECTS AND METHODS: Doppler velocimetry indices (maximum peak systolic velocity during ventricular systole, end-diastolic velocity during atrial contraction, peak systolic velocity/end-diastolic velocity ratio and pulsatility index for veins) were successfully measured three times by the same trained observer in 67 fetuses. Of these, in 24 fetuses, the measurements were then repeated by a second trained observer. In addition, both observers classified qualitatively the blood flow as being normal or abnormal with regard to the presence or absence/reversal of flow during atrial contraction. RESULTS: The intraobserver repeatability of the pulsatility index for veins measurements was considered good with a coefficient of variation of 8.9% and an intraclass correlation coefficient value of 0.62. However, inconsistencies occurred in maximum peak systolic velocity, end-diastolic velocity and systolic/diastolic ratio measurements, which had coefficients of variation of 19%, 28.5%, and 25.4%, respectively. The corresponding intraclass correlation coefficient values were 0.70, 0.69 and 0.60. Interobserver reproducibility of these indices was unsatisfactory, the coefficient of variation varying between 11.5% and 47.2% and the intraclass correlation coefficient between 0.18 and 0.44. Agreement between the repeated observations with regard to interpretation of normal or abnormal blood flow varied from moderate (interobserver) to very good (intraobserver). CONCLUSIONS: There was considerable variability in all Doppler indices except for the intraobserver repeatability of the pulsatility index for veins measurement. This makes the implementation of the semiquantitative Doppler indices in a screening setting difficult. On the contrary, qualitative classification of the flow velocity waveforms seemed to be a reproducible method.