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。     

Serial sonographic findings of four fetuses with homozygous alpha-thalassemia-1 from 21 weeks onwards.

OBJECTIVES: To evaluate the potential usefulness of noninvasive ultrasound assessment of fetal anemia in the diagnosis and management of fetuses with homozygous alpha-thalassemia-1. METHODS: We describe four pregnancies complicated by fetal homozygous alpha-thalassemia-1. They presented with ultrasound abnormalities before the development of hydrops. As part of evaluating the fetal condition, we performed ultrasound and Doppler studies aimed at identifying fetal anemia. These studies included evaluation of intrahepatic umbilical venous maximum flow velocity, middle cerebral artery peak flow velocity, fetal liver length and spleen perimeter. RESULTS: In all four fetuses, ultrasound and Doppler studies suggested the presence of fetal anemia. Homozygous alpha-thalassemia-1 was diagnosed in all cases, with fetal blood sampling confirming anemia in three fetuses. The majority of the intrahepatic umbilical venous maximum flow velocity and middle cerebral artery peak flow velocity measurements were above the 95th centile. Two fetuses underwent intrauterine transfusion and fetal blood flow velocities returned to normal after correction of the fetal anemia. The fetal liver length and spleen perimeter measurements showed a similar trend, although they were less consistent before 28 weeks. CONCLUSION: Non-invasive ultrasound parameters, in particular quantification of intrahepatic umbilical venous maximum flow velocity and middle cerebral artery peak flow velocity, were found to be useful in the diagnosis and management of fetal anemia in pregnancies with fetal homozygous alpha-thalassemia-1.     

Cardiac defects in chromosomally normal fetuses with abnormal ductus venosus blood flow at 10-14 weeks.

OBJECTIVE: To assess a possible relationship between ductus venosus blood flow abnormalities and cardiac defects in chromosomally normal fetuses with increased nuchal translucency thickness at 10-14 weeks of gestation. METHODS: Ductus venosus Doppler ultrasound blood flow velocity waveforms were obtained at 10-14 weeks' gestation immediately before fetal karyotyping in 200 consecutive singleton pregnancies with increased nuchal translucency. Fetal echocardiography was subsequently carried out in those with normal fetal karyotype. RESULTS: Reverse or absent flow during atrial contraction was observed in 11 of the 142 chromosomally normal fetuses with increased nuchal translucency. Major defects of the heart and/or great arteries were present in seven of the 11 with abnormal ductal flow and increased nuchal translucency, but in none of the 131 with normal flow. CONCLUSION: These preliminary results suggest that abnormal ductus venosus blood flow in chromosomally normal fetuses with increased nuchal translucency identifies those with an underlying major cardiac defect.     

Jugular vein and carotid artery blood flow in fetuses with increased nuchal translucency at 10-14 weeks' gestation.

OBJECTIVE: The aim of our study was to obtain measurements of the jugular vein and carotid artery pulsatility index (PI) at 10-14 weeks' gestation in chromosomally normal and abnormal fetuses with or without increased nuchal translucency (NT), in order to explore whether a relationship exists between increased NT and overperfusion of the head. METHODS: This was a prospective study involving 179 pregnant women at high risk for chromosomal anomalies or structural malformations who were referred for chorionic villus sampling or first-trimester ultrasound examination at 10-14 weeks' gestation, respectively. Color and pulsed Doppler ultrasound were used to obtain jugular vein and carotid artery blood flow velocity waveforms at the level of the mid-neck. All Doppler measurements were obtained by a single investigator. The PIs of the jugular vein and carotid artery were correlated with NT measurement and fetal karyotype. RESULTS: Doppler measurements of the jugular vein and carotid artery were successfully obtained in 90.5% of the fetuses. The fetal karyotype was abnormal in 13 cases, including three trisomies 21 and two trisomies 18, and normal in 149 cases. In the group with normal karyotype the NT was above the 95th percentile in 22 cases (15%). No correlation between the jugular vein or the carotid artery PI and the thickness of the NT was found. There were no significant differences when comparing the values of the jugular vein and carotid artery PI between the group with normal NT and the group with increased NT, or between the group with a normal karyotype and an abnormal karyotype. CONCLUSION: Our results suggest that NT is not related to blood flow impedance in either the carotid artery or the jugular vein. Overperfusion and venous congestion of the head do not appear to be a causative pathophysiological mechanism involved in increased NT.     

Fetal cardiac arrhythmias and their effect on volume blood flow in descending aorta of human fetus

Using a two-dimensional linear array real-time and pulsed Doppler ultrasound system, volume blood flow measurements were made in 86 normal pregnancies, seven cases of fetal bradycardia, and seven cases of fetal tachycardia at the lower thoracic level of the fetal descending aorta. During fetal cardiac arrhythmias, volume blood flow was maintained within the normal range until the heart rates reached around 50 bpm and 230 bpm, after which the volume blood flow diminished. The changes observed suggest that the Frank-Starling mechanism is functional in the fetal myocardium and demonstrate the stability of the fetal circulation.     

The role of fetal nuchal translucency and ductus venosus Doppler at 11-14 weeks of gestation in the detection of major congenital heart defects.

OBJECTIVE: To determine whether, in a selected high-risk population, Doppler velocimetry of the ductus venosus can improve the predictive capacity of increased nuchal translucency in the detection of major congenital heart defects in chromosomally normal fetuses at 11-14 weeks of gestation. METHODS: Ductus venosus Doppler ultrasound blood velocity waveforms were obtained prospectively at 11-14 weeks of gestation in 1040 consecutive singleton pregnancies. Waveforms were classified either as normal in the presence of a positive A-wave, or as abnormal if the A-wave was absent or negative. All cases were screened for chromosomal defects by a combination of maternal age and fetal nuchal translucency thickness. In 484 cases karyotyping was performed. Those fetuses found to be chromosomally normal by prenatal cytogenetic analysis, and which had abnormally increased nuchal translucency and/or abnormal ductus venosus Doppler velocimetry, underwent fetal echocardiography at 14-16 weeks of gestation. Ultrasound examination was repeated at 22-24 weeks of gestation in all women. The sensitivity, specificity and positive and negative predictive values for the detection of major cardiac defects of increased nuchal translucency thickness alone, ductus venosus Doppler alone and increased nuchal translucency thickness in association with abnormal ductus venosus Doppler were determined. RESULTS: In 29 of 998 fetuses presumed to be chromosomally normal, reversed or absent flow during atrial contraction was associated with increased (> 95(th) centile for crown-rump length) nuchal translucency. Major cardiac defects were observed in 9 of these 29 fetuses. No other major cardiac abnormalities were found in chromosomally normal fetuses in spite of the presence of either increased nuchal translucency alone or abnormal ductus venosus velocimetry. A total of 25 cardiac malformations were observed in the population. Fifteen were associated with aneuploidy and 10 fetuses had a normal karyotype. Nine of the 10 had major cardiac anomalies and one had a ventricular septal defect. The nine cases with normal karyotype and major cardiac anomalies had both increased nuchal translucency and abnormal ductus venosus flow velocity waveforms. CONCLUSION: In chromosomally normal fetuses with increased nuchal translucency, assessment of ductus venosus blood flow velocimetry could improve the predictive capacity for an underlying major cardiac defect.     

Doppler analysis of the umbilical artery. The importance of choosing the placental end of the cord

Thirty normal pregnancies were studied with continuous or pulsed Doppler ultrasound (50 measurements). The ratio of systolic (S) to end-diastolic (D) measurement, or S/D ratio, was obtained at both ends of the cord: the placental insertion and the fetal abdominal insertion. A statistically significant difference was demonstrated between the two sets of measurements. Normal values were obtained at the placental insertion, whereas, simultaneously, the fetal abdominal insertion generated highly abnormal values. When performing Doppler waveform analysis of the umbilical artery, if abnormal values are obtained, one should be cautious to be certain that they originated from the placental insertion.     

Doppler velocimetry, placental morphology and outcome in insulin-dependent diabetes.

The purpose of this study was to determine the underlying cause of abnormal umbilical artery Doppler velocimetry in pregnancies complicated by insulin-dependent diabetes, by evaluating placental morphology and correlating Doppler results with pregnancy outcome. Our study population consisted of 14 pregnancies with normal Doppler results and 11 pregnancies with abnormal Doppler results. Quantitative placental examinations were performed. Maternal and perinatal characteristics were analyzed. Infants from the abnormal Doppler group had a statistically significantly higher incidence than those from the normal Doppler group of hyperbilirubinemia, Cesarean delivery for fetal distress, and neonatal intensive care stay of 2 or more days. Women with abnormal Doppler results delivered earlier (36 vs. 38 weeks) and had infants of lower birth weight (3079 vs. 3629 g). They were also three times more likely to have poor glycemic control (relative risk = 3.2; p = 0.0067). The placentae of both groups showed no statistically significant differences in placental weight, number of tertiary stem villi, number of small muscular arteries, or mean arterial width. Our findings suggest a functional rather than structural placental process as the cause of the abnormal Doppler results in pregnancies complicated by diabetes. An association between glycemic control and Doppler velocimetry is suggested.     

Doppler velocimetry and the assessment of fetal well-being in normal and diabetic pregnancies.

Doppler ultrasound has been proposed as a useful addition to antepartum testing in high-risk pregnancies. Increased placental resistance has been associated with underlying placental vascular disease, as well as abnormal fetoplacental blood flow. Since pregnancies complicated by diabetes are at risk for these complications, the application of Doppler ultrasonography for such pregnancies has been evaluated by several investigators.Multiple investigations have examined the relationship between maternal blood glucose levels and abnormal Doppler waveforms in women with diabetes. Of the nine published studies, four found a correlation between Doppler indices and glucose control, as measured by mean blood glucose levels and glycosylated hemoglobin levels, while five did not. However, this apparent discrepancy may be explained by the fact that the majority of women studied were in good or excellent control, as this is currently the accepted standard of care. In fact, the one study performed in primarily non-diabetic women demonstrated that increases in maternal plasma glucose concentrations of 30 mg/dl were followed by significant rises in the mean pulsatility index in both the umbilical and carotid arteries. More dramatic was the finding by most investigators that systolic/diastolic (S/D) ratios in third-trimester umbilical arteries were elevated in women with evidence of diabetic microvascular disease. Elevated third-trimester S/D ratios were associated with adverse maternal and perinatal outcomes in these women, specifically pre-eclampsia and intrauterine growth retardation.In conclusion, although elevated Doppler indices correlated with adverse outcomes in diabetic pregnancies, Doppler indices may be elevated in the otherwise uncomplicated diabetic patient with associated microvascular disease and with a normal outcome. Therefore, the Doppler ultrasound assessment of fetal well-being in diabetic pregnancies must be interpreted with caution.     

Fetal cerebral venous Doppler velocimetry in normal and high-risk pregnancy.

OBJECTIVE: In previous pilot studies, fetal vein of Galen (GV) blood velocity has been shown to be non-pulsatile in normal pregnancies. A pulsating pattern in high-risk pregnancies has been related to adverse outcome of pregnancy. The aim of this study was to establish reference ranges for fetal cerebral venous blood flow and compare them to the recordings in high-risk pregnancies in terms of predicting adverse perinatal outcome. METHODS: The GV, straight sinus (SS) and transverse sinus (TS) were located by color Doppler ultrasound in 189 normal pregnancies between 23 and 43 weeks of gestation. Recordings were also made in 102 pregnancies complicated by pregnancy-induced hypertension and/or intrauterine growth restriction. The following parameters were measured: peak systolic velocity, minimum diastolic velocity, time-averaged maximum velocity, pulsatility index for veins (PIV) and preload index (PLI). GV pulsations were noted. In high-risk pregnancies, Doppler measurements were correlated to pregnancy outcome, including emergency operative intervention and/or neonatal distress. Umbilical vein and umbilical, uterine and middle cerebral artery blood velocities were also recorded at the same time. RESULTS: In normal pregnancy, pulsating venous blood velocity was observed in GV in 8% of cases, in SS in 79% of cases and in TS in 100% of cases. GV and SS maximum velocity increased with gestational age and TS-PIV showed linear decreasing values and TS-PLI showed increasing values with gestational age. In high-risk pregnancies, pulsating blood velocity in the GV was found in 59 (58%) cases and was related to adverse outcome of pregnancy including mortality. Abnormal values for TS-PIV and PLI and SS maximum velocity were found in nine, six and five cases, respectively and were only related to perinatal mortality. GV pulsations were more frequent than umbilical venous pulsations. CONCLUSIONS: Of the fetal cerebral veins studied, the presence of pulsations in the GV seems to be the best predictor of adverse outcome of high-risk pregnancy. Pulsations in the GV are more frequent than in the umbilical vein and might therefore appear earlier during worsening fetal condition, and thus be of potential value for fetal surveillance in high-risk pregnancies.     

Placental blood flow measured by simultaneous multigate spectral Doppler imaging in pregnancies complicated by placental vascular abnormalities.

OBJECTIVE: To evaluate the role of placental blood flow measurements by simultaneous multigate spectral Doppler imaging in pregnancies complicated by intrauterine growth restriction (IUGR), and for early detection of placental vascular abnormalities in high- and low-risk pregnancies. METHODS: To assess the sensitivity and specificity of abnormal placental blood flow in detecting IUGR, we followed 22 women whose pregnancies were complicated by IUGR at 28-34 weeks' gestation, and compared the findings with those obtained in 22 matched controls. We defined placental blood flow impedance as abnormal when 10% of placental pulsatility index (PI) measurements were greater than, or equal to, the mean umbilical artery PI (placental PI/umbilical PI > or = 1). To determine the predictive value of abnormal placental blood flow measurement for identifying developing uteroplacental insufficiency, we examined an unselected group of 100 low- and high-risk patients at 20-22 weeks' gestation. We correlated the Doppler findings with the development of pre-eclampsia, IUGR, placental abruption, oligohydramnios and the presence of persistent late decelerations during labor. RESULTS: Placental blood flow determination was more sensitive than umbilical artery blood flow in detecting abnormal umbilical-placental flow impedances as manifested by the presence of IUGR. Of the 100 mixed high- and low-risk patients examined at 20-22 weeks, 32 had abnormal placental blood flow. Of these, 19 (59.4%) subsequently developed pathologies associated with placental vascular disease. Of the 68 patients with normal placental blood flow, only six (8.8%) developed such pathologies. The sensitivity was 76% (19/25), with positive predictive value 59.4% (19/32); the specificity was 82.7% (62/75), with negative predictive value 91.2% (62/68). CONCLUSIONS: Abnormal intraplacental blood flow at 28-34 weeks' gestation is strongly associated with IUGR. In addition, it has moderate positive and negative predictive values for identifying subsequent development of uteroplacental vascular abnormalities.     

多普勒超声检测胎儿心脏机械性PR间期的临床意义研究

目的应用多普勒超声技术测量胎儿心脏机械性PR间期并探讨其临床意义。方法选取经胎儿超声心动图检出的83例疾病组胎儿,分别为先天性心脏病及心律失常。正常对照组为100例中、晚孕胎儿。应用彩色多普勒引导脉冲多普勒取样容积记录左心室流入道及流出道血流频谱,测量从舒张期二尖瓣A峰起始至收缩期主动脉射血起始的心房到心室的传导时间(PR间期),并同时测量收缩期主动脉射血起始至二尖瓣A峰起始的时间(VA间期)。结果 83例疾病组胎儿中先天性心脏病69例,心律失常12例,双胎输血综合征1例(双胎儿)。其中54例多普勒超声测量PR间期延长(131～220ms),并检出自身免疫性抗体阳性和弱阳性5例。正常对照组100例的中、晚孕孕妇均无自身免疫系统疾病,并经超声排除胎儿先天性心脏病、心律失常及其他胎儿异常,多普勒超声测量PR间期值均≤130ms。两组PR间期、VA间期比较差异有统计学意义(P0.01)。结论本研究结果表明,除孕妇患自身免疫性疾病可引起胎儿传导系统受损外,胎儿患先天性心脏病、心律失常等疾病时,其窦房结、房室结传导功能的易损性明显高于正常胎儿。其影响因素与心脏解剖结构异常和传导系统发育不良的相关性有待进一步研究。     

孕早期颈项透明层超声联合孕中期彩色多普勒超声可提高产前胎儿畸形检出率

目的探究孕早期颈项透明层（NT）超声联合孕中期彩色多普勒超声在产前胎儿畸形筛查中的应用价值。方法选择2017年8月~2019年12月在我院行胎儿畸形筛查的2417例孕妇作为研究对象,所有孕妇于孕11~14周行NT超声检查,并于孕22~28周行二维、四维彩超检查。以引产或分娩结果为“金标准”,比较畸形胎儿、正常胎儿的NT值及NT异常率,对比NT超声检查、二维联合四维彩超检查结果,并就NT超声、二维及四维彩超及二者联合在诊断胎儿畸形中的诊断率进行比较。结果2417例孕妇最终确诊异常胎儿88例,发病率为3.64%。畸形胎儿的NT值明显高于正常胎儿,NT异常率（93.18%）明显高于正常胎儿（1.33%）,差异比较有统计学意义（P < 0.05）。NT超声检查共检出异常胎儿82例,诊断准确率为93.18%;二维联合四维彩超共检出异常胎儿85例,诊断准确率为96.59%。二维联合四维彩超的诊断准确率略高于NT超声检查,差异无统计学意义（P>0.05）。NT超声联合二维、四维彩超在诊断胎儿畸形中的敏感度、特异度和准确度分别为100.00%、99.57%、99.59%,高于NT超声、二维和四维彩超（分别为93.18%、98.67%、98.47%和96.59%、99.06%、98.97%）,组间比较差异有统计学意义（P < 0.05）。结论孕早期NT超声及孕中期彩色多普勒超声在产前筛查胎儿畸形上各具有优势,均具有较好的诊断价值。二者联合应用能够进一步提升胎儿畸形的检出率,对尽早终止胎儿畸形孕妇继续妊娠,减少畸形胎儿出生具有重要意义。     

Umbilical venous pulsatility and volume blood flow in complicated pregnancies: Correlation with the umbilical artery blood velocity waveforms

The purpose of this retrospective work was to evaluate Doppler recorded umbilical venous volume blood flow in complicated pregnancies with abnormal umbilical venous pulsatility. During 1632 examinations abnormal pulsatility was found in 14 fetuses having normal volume flow. There were four perinatal deaths, all in pregnancies with absent blood velocity in the umbilical artery and abnormal umbilical venous pulsatility, suggesting that measurements of umbilical venous blood velocity should be included in the surveillance of pregnancies with absent diastolic blood velocity.     

Fetal and placental power Doppler imaging in normal and high-risk pregnancy.

OBJECTIVE: Computer analysis of organ power Doppler (PD) imaging has recently become available. The aim of the study was to evaluate gestational trends in placenta-, fetal lung-, liver- and kidney-blood flow in normal pregnancies and relate it to signals in high-risk pregnancies. METHODS: PD signals were recorded in normal singleton pregnancies between 26 and 42 weeks of gestation. Signals were also recorded in 63 high-risk pregnancies. Fixed preinstalled PD system installations for each organ were used during examinations. Images from PD scan were recorded on video tape and off-line analysed by computer. Mean flow signal intensity was calculated for each organ. Umbilical and uterine artery Doppler velocimetry were also recorded in high-risk pregnancies. RESULTS: PD signals from the four organs indicated increasing organ blood flow until approximately 34 weeks of gestation, from where the organ signals seemed to decrease. High-risk pregnancies seemed to have lower PD signal intensity, which was more pronounced in cases with signs of placental vascular resistance. CONCLUSION: The results suggest that a decrease in fetal organ blood flow might indicate a centralisation of fetal circulation in normal pregnancy at term, as a physiological response to a decrease in placental perfusion. In the high-risk pregnancies the placental and fetal organ blood flow seem to be even further reduced, suggesting a more intense centralisation of circulation.     

Ultrasonographic markers for chromosomal abnormalities in women with negative nuchal translucency and second trimester maternal serum biochemistry.

OBJECTIVE: To analyze the value of second trimester ultrasound examination among those women whose fetuses were indicated to be at low risk of chromosomal anomalies on the basis of both first trimester nuchal translucency measurement and second trimester biochemical screening. METHODS: A retrospective study of 5500 pregnancies carried out at the fetal medicine unit, Royal Free Hospital. During a period of over 3 years 5500 pregnancies underwent a first trimester scan and nuchal translucency measurement which enabled the detection of 62% (20 of 32) of all chromosomal anomalies. From the remaining pregnancies that underwent second trimester biochemical screening, 3548 were considered negative (risk < 1:250; using maternal serum free beta human chorionic gonadotrophin and alpha fetoprotein). The ultrasound markers that were examined were: shortened femur length, echogenic bowel, pyelectasis, choroid plexus cysts and echogenic intracardiac foci. The likelihood ratios for chromosomal aneuploides for each of these markers were calculated. RESULTS: Of the 3548 screen negative pregnancies, 3541 (99.8%) had a normal karyotype. Seven (0.2%) fetuses had an abnormal karyotype including four (0.11%) with trisomy 21, one with trisomy 18 and two with 47XXY. Second trimester ultrasound markers were found in two of the five (40%) with severe chromosomal anomalies compared to 184 of 3541 (5.2%) with normal karyotypes. Detection of one or more ultrasound markers in a screen negative pregnancy increased the possibility of chromosomal aneuploidy and a negative ultrasound decreased the risk by a likelihood ratio of 0.6 (95% confidence interval, 0.3-1.3). The risk was considerably increased when two or more markers were detected and we would recommend karyotyping under these circumstances. CONCLUSION: This preliminary data indicates a possible role for abnormal ultrasound markers in assessing the risk of chromosomal abnormalities in patients considered to be at low risk by nuchal translucency and serum screening. However analysis of a much larger study group will have to be conducted to assess the significance of individual markers.     

Uterine-umbilical artery Doppler velocimetry in pregnant women with systemic lupus erythematosus.

We evaluated continuous wave uterine-umbilical artery Doppler velocimetry for predicting pregnancy outcome in women with systemic lupus erythematosus (SLE). Lupus anticoagulant (LAC) and anticardiolipin (ACL) antibody status also were correlated with Doppler results and outcome. Three Doppler vascular patterns were identified in 27 pregnancies of 26 women with SLE. Patients with normal flow velocity in both vessels had normal outcomes (n = 18). Reduced flow velocity of the umbilical artery only was present in five women, whose newborn infants were of lesser gestational age and birthweight, two being small for gestational age. In four pregnancies reduced flow velocity was noted in both vessels. These cases had the poorest outcome, with three perinatal losses and all fetuses being small for gestational age. Doppler velocimetry showed 100% sensitivity and negative predictive value in the detection of the small for gestational age fetus and abnormal antepartum fetal heart rate tracing. Fourteen of 18 women with normal Doppler studies did not have preeclampsia or SLE flare-ups, whereas all nine women with abnormal Doppler studies had such complications. In all 27 pregnancies the women were screened for LAC, and 21 women also were tested for the ACL antibody. Poor correlation was found between antiphospholipid antibody status and Doppler results in three of the six pregnancies with positive antibody testing the patients had normal Doppler studies and outcomes. Thus, Doppler velocimetry may help determine when these substances will affect the outcome adversely. In this study the umbilical-placental vascular system was affected more often. Uterine-umbilical arterial Doppler velocimetry uniquely identified the fetus at risk for adverse perinatal outcome in pregnancies complicated by SLE. Thus, it is a potentially valuable tool in clarifying the pathophysiology and in the management of SLE in pregnancy.     

Comparison of the prognostic value of pulsed Doppler blood flow parameters to predict SGA and fetal distress.

A total of 219 women with complicated pregnancies had Doppler assessment of uteroplacental arteries, the umbilical artery, the fetal common carotid artery and the descending thoracic aorta to determine the prognostic value of Doppler examinations to predict the birth of a small-for-gestational-age (SGA) infant with or without fetal distress. Preliminary reproducibility studies showed that the resistance index, pulsatility index and intensity weighted flow velocity had the lowest coefficients of variation. Data on the systolic/diastolic ratio and mean blood flow volume were, therefore, not considered for further evaluation.Measurements were classified according to the time interval of the examination to the delivery of the baby according to the following groupings: 0-14 days, 15-28 days and 29-42 days. For evaluation of the SGA fetus complicated by fetal distress, only measurements within 2 weeks of delivery were analyzed. Significant differences were calculated by considering the area below the receiver operator characteristic (ROC) curves.Only Doppler studies of the uteroplacental arteries (mainly resistance index) were predictive of the later development of the SGA fetus. All fetal parameters showed an increasing improvement in the predictive capacity for an SGA infant, the closer the measurements were made to the time of delivery. This improvement was not observed for uteroplacental vessels.The resistance index of the uteroplacental vessels was significantly higher in SGA pregnancies complicated by fetal distress compared to SGA pregnancies alone. However, ROC analysis revealed that fetal Doppler velocimetry was more strongly related to fetal distress than SGA only. The single best fetal parameter was the mean velocity in the fetal descending thoracic aorta but the velocity ratio of the fetal common carotid artery over the fetal descending thoracic aorta had the highest predictive capacity for the SGA pregnancy complicated by fetal distress.     

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.     

Prenatal diagnosis of abnormalities of the fetal venous system.

OBJECTIVE: To present our experience in the prenatal diagnosis of anomalies of fetal veins using high-resolution color Doppler ultrasound. DESIGN: An observational study of 16 fetuses with abnormalities of the umbilical, portal, hepatic and caval venous system being diagnosed at the Division of Prenatal Diagnosis and Therapy (Bonn, Germany) over the past 5 years. The abnormality of the venous system, the underlying embryologic disorder and the outcome of the pregnancy are presented and compared with the literature. RESULTS: In group A, eight fetuses had an abnormal course of the umbilical vein with a patent (n = 3) or absent (n = 5) ductus venosus. No portal veins and absent or abnormal hepatic veins were visualized by color Doppler sonography. Six fetuses (75%) did not have an associated malformation and have survived. Two pregnancies with fetal hydrops due to a small heart and to Turner's syndrome were terminated or ended in fetal demise. In group B, seven of eight fetuses with an abnormal caval system had a situs ambiguus or an atrial isomerism. A cardiac defect was detected in six cases (86%). These six pregnancies ended in four terminations of pregnancy and two infant deaths due to the severity of the congenital cardiac defect. One child with a normal heart and a child with an isolated abnormal course of the lower inferior vena cava are developing well. CONCLUSIONS: In a targeted fetal scan the course of the umbilical vein, ductus venosus, the portal and hepatic veins and inferior vena cava should be carefully examined using color Doppler. Any suspicious finding should be followed by a detailed assessment of the specificity of this abnormality taking into consideration the embryologic development of the fetal venous system together with the associated malformations.