The value of Doppler velocimetry in umbilical and cerebral artery in pregnancy complicated by IUGR and its influence on mode of delivery and neonatal Apgar score

The most important diagnostic method in pregnancy complicated by IUGR is Doppler flow velocity in placento-fetal circulation. The most useful diagnostic method is the umbilical and pulsatility index and cerebro-placental ratio. DESIGN: The aim of the study is to evaluate the value of pulsatility index umbilical and cerebro-placental ratio in intrauterine growth restriction, the way of delivery and neonatal Apgar score. MATERIAL AND METHODS: The study was done in Dep. of Obstetrics and Gynaecology Medical University in Lodz in 2001-2005 y. The study group consists of 80 women with diagnosed IUGR, control group--50 healthy pregnant women at the same gestational age. The Doppler flow measurement in umbilical and middle cerebral arteries, the way of delivery and Apgar score were estimated. RESULTS: In the group of IUGR in 11 cases the PI value in umbilical artery increased, in 3 cases of this group cerebro-placental ratio was elevated. In control group evaluated blood flow indexes were normal. The ratio of caesarian sections in growth-restricted fetuses group was higher than in control group. The neonatal Apgar score was similar in compared groups. CONCLUSION: In pregnancy complicated by IUGR the Doppler flow measurement was useful to found fetal intrauterine hypoxia.     

Receiver operating characteristic curves of fetal, umbilical and uteroplacental blood velocity waveforms as predictors of fetal outcome

The maximum blood flow velocity waveforms (FVW) were recorded by a pulsed Doppler ultrasound from the fetal aorta, umbilical artery and arcuate artery in 142 pregnancies suspected of intrauterine growth retardation (IUGR) according to ultrasound fetometry. The FVW were analysed for pulsatility index (PI) and Blood Flow Class (BFC). The aim of the study was to find the optimal parameter and cut-off level for predicting the outcome of pregnancy. Receiver operating characteristic curves were used for the analysis. The umbilical artery PI and BFC shows the strongest relationship to IUGR. The optimal cut-off point was found at 2 SD above the mean PI of the normal population. The aortic PI had a relatively low predictive value for IUGR, but the absence of aortic end-diastolic velocities (BFC 2 and 3) was the best parameter for predicting fetal distress. The arcuate artery PI had low predictive capacity for fetal outcome. The data indicate that the absence of diastolic velocities in the fetal aorta and the umbilical artery PI, with the cut-off level of 2 SD above the mean for the normal population, are the best and comparable blood flow parameters, which can be used for monitoring fetuses suspected of IUGR.     

Umbilical and middle cerebral artery Doppler indices in patients with preeclampsia

OBJECTIVE: To compare changes in Doppler ultrasound studies of fetal circulation in normal pregnancies with those of a group of preeclamptic patients both with and without intrauterine growth retardation and to demonstrate the best index for predicting adverse perinatal outcome or IUGR. STUDY DESIGN: A cross-sectional study was performed on 125 normal pregnancies and 62 preeclamptic patients at 31-40 weeks of gestation. The umbilical artery systolic-diastolic ratio (UA S/D), UA pulsatility index (PI), the middle cerebral artery (MCA) PI, and the ratio of MCA PI to UA PI were measured. The mean values of the Doppler indices were compared. Different cut-off values (mean +/-2 S.D.) were used for the 31st-35th and the 36th-40th weeks. RESULTS: Significant differences were found between normal pregnancies and preeclamptic patients without IUGR using the mean MCA PI and the MCA PI/UA PI ratio. In the preeclamptic patients with IUGR, all the mean Doppler indices were different from those of the normal pregnancies. In the preeclamptic patients with IUGR the values were different from the preeclamptic patients without IUGR, except for the MCA PI at 31-35 weeks. The UA S/D had the highest sensitivity (88%) and diagnostic accuracy (94%) in predicting the adverse perinatal outcome. The MCA PI/UA PI ratio showed the highest predictive value in determining IUGR by a sensitivity of 84% and a diagnostic accuracy of 87%. CONCLUSION: Both abnormal umbilical Doppler indices and cerebral-umbilical ratio are strong predictors of IUGR and of adverse perinatal outcome in preeclampsia. The MCA PI alone is not a reliable indicator. The combination of umbilical and fetal cerebral Doppler indices may increase the utility of Doppler ultrasound in preeclamptic subjects.     

Fetal blood flow in pregnancies complicated by intrauterine growth retardation

A noninvasive pulsed Doppler ultrasound technique was used to characterize blood flow in the descending thoracic aorta and the intra-abdominal part of the umbilical vein in 159 fetuses suspected of intrauterine growth retardation (IUGR) on the basis of ultrasound fetometry. From this group, 74 infants with IUGR (defined as gestational age-related birth weight of 2 standard deviations [SD] or more below the population mean) were born. The blood flow results were not available to the clinicians managing the pregnancies. Blood flow mean velocity in the fetal aorta was lower, pulsatility index and rising slope higher, and umbilical volume flow and umbilical flow per 100 g placental tissue were lower in the pregnancies with IUGR than in 21 normal pregnancies. The waveform of the maximum aortic velocity envelope was related to operative delivery for fetal distress, Apgar score, and umbilical cord blood pH. The pulsatility index and the configurational assessment of the diastolic part of the waveform were combined to form a new concept, the blood flow class. The blood flow class was abnormal in 57% of the fetuses classified as having IUGR at birth and in 93% of those growth-retarded fetuses who subsequently developed signs of fetal distress requiring operative delivery. Waveform analysis, in terms of blood flow class, seems to be a useful tool in the surveillance of fetuses when IUGR is suspected. Abnormal blood flow class is a marker of fetal distress and probably gives an earlier indication than antenatal nonstressed cardiotocography. The results of this study point to a strong association between IUGR and impaired fetal blood flow. The aortic volume blood flow, unlike waveform analysis, does not seem to be a variable sensitive enough to predict fetal outcome in the individual pregnancy.     

Blood velocity waveforms in the fetal aorta and umbilical artery as predictors of fetal outcome: a comparison

In 139 pregnancies in which intrauterine growth retardation (IUGR) was suspected at routine ultrasound screening at 32 weeks of gestation, blood velocity in the fetal aorta and umbilical artery was recorded by a pulsed Doppler ultrasound every second week until delivery. The maximum blood flow velocity waveforms (FVWs) were analyzed for pulsatility index (PI) and blood flow class (BFC). In both vessels, an abnormal PI (greater than mean + 2 SD of the normal population) and abnormal BFC at the final antenatal examination were significantly associated with the occurrence of IUGR (birthweight less than or equal to mean - 2 SD) (p less than 0.001), operative delivery for fetal distress (p less than 0.001), and a low 1-minute Apgar score (less than or equal to 7). PI in the umbilical artery was a better predictor of fetal outcome than was the aortic PI, but the BFC was similarly predictive of fetal outcome in both vessels. The data indicate that a simple umbilical artery examination, which can be performed blindly with the Doppler ultrasound instrument without the help of a real-time scanner, is a reliable method for monitoring fetal status in pregnancies when IUGR is suspected.     

Ultrasound measurement of fetal blood flow in predicting fetal outcome

The efficacy of fetal blood flow assessment in predicting fetal outcome was evaluated in 159 pregnancies suspected of intrauterine growth retardation (IUGR). Blood flow in the fetal aorta and umbilical vein was measured with imaging and pulsed Doppler ultrasound. Volume blood flow values and variables describing the waveform of the maximum aortic blood velocity were checked for relations to subsequent fetal outcome. A new semi-quantitative velocity waveform variable, blood flow class (BFC), was designed and tested. The occurrence of IUGR, imminent fetal distress, a low Apgar score at 1 and 5 min, and a low pH in the umbilical artery and vein were adopted to characterize fetal outcome. Receiver operating characteristic curves were used to demonstrate the sensitivity and false positive rate, and the Cohen's Kappa index was used to compare the predictive capacity of the various blood flow variables. BFC, describing the blood velocity waveform with emphasis on its end-diastolic part, was found to be the most powerful marker of imminent fetal asphyxia (Kappa = 0.66) and of intrauterine growth retardation (Kappa = 0.48).     

Ultrasound measurement of fetal blood flow in predicting fetal outcome

Summary. The efficacy of fetal blood flow assessment in predicting fetal outcome was evaluated in 159 pregnancies suspected of intrauterine growth retardation (IUGR). Blood flow in the fetal aorta and umbilical vein was measured with imaging and pulsed Doppler ultrasound. Volume blood flow values and variables describing the waveform of the maximum aortic blood velocity were checked for relations to subsequent fetal outcome. A new semi-quantitative velocity waveform variable, blood flow class (BFC), was designed and tested. The occurrence of IUGR, imminent fetal distress, a low Apgar score at f and 5 min, and a low pH in the umbilical artery and vein were adopted to characterize fetal outcome. Receiver operating characteristic curves were used to demonstrate the sensitivity and false positive rate, and the Cohen's Kappa index was used to compare the predictive capacity of the various blood flow variables. BFC, describing the blood velocity waveform with emphasis on its end-diastolic part, was found to be the most powerful marker of imminent fetal asphyxia (Kappa = 0.66) and of intrauterine growth retardation (Kappa—0.48).     

Study of Doppler flow velocity wave forms of the fetal umbilical artery

400 umbilical arterial wave forms were determined in 120 cases of normal pregnancy. The systolic/diastolic (S/D) ratio of umbilical doppler flow velocity wave declined gradually from 3.3 to 2.2 during the period of 28th to 40th week, It was shown that the utero resistance was reduced and the placental blood perfusion was good. 67 umbilical arterial wave forms were determined in 33 cases of pregnancy induced hypertension. There were 20 cases of IUGR or fetal distress with abnormal umbilical arterial S/D ratio. The incidence of IUGR was 27% (9/33). The results show that this is a good, non-invasive and practical method for predicting fetal outcome. In combination with NST and biophysical profile it can serve as an antepartum assessment of fetal well being and is of much valve to eugenics and perinatology.     

宫缩期脐血流与胎儿宫内窘迫的相关性分析

目的 :通过检测产程处于潜伏期的孕妇宫缩时的脐动脉血流变化 ,了解宫缩对胎儿的影响 ,探讨脐血流预测胎儿宫内窘迫的价值。方法 :采用彩色多普勒超声血流诊断技术 ,对 4 7例处于潜伏期的孕妇分别进行宫缩期及间歇期脐动脉检测。结果 :33例检测结果正常 ,14例异常 (宫缩期 S/ D>2 .7)。两组比较 ,除 MAX以外 ,宫缩期及间歇期各项指标都有差异 ,且胎儿窘迫的发生也有差异 ;组内分析 ,异常组的 MIN的降幅对比 MAX的降幅有统计学差异。结论 :超声多普勒脐血流产时检测 ,可以作为预测胎儿宫内窘迫的筛选实验。其敏感性、特异性、阳性预测值、阴性预测值分别是 :83.3%、93.5 %、83.3%和 93.5 %。     

Middle cerebral artery Doppler indices better predictor for fetal outcome in IUGR

Objective(s)

To compare the role of middle cerebral artery and umbilical artery Doppler pulsatility indices in predicting the fetal outcome in intrauterine growth restriction.

Method(s)

The prospective study was conducted on 121 subjects. They were divided into two groups. The study group (n=71) consists of high risk group of pregnant women with growth restricted fetuses. The control group (n=50) consists of pregnant women with healthy fetuses. Both the groups were evaluated by middle cerebral artery and umbilical artery velocimetry between 28 and 41 weeks of pregnancy.

Results

Mothers with abnormal velocimetry had more number of cesarean sections to prevent fetal distress than those with normal velocimetry. The subjects with high risk factors had more number of abnormal waveforms than those without high risk factors. The predictive value of Doppler P.I for detecting abnormal fetal outcome was 94% in middle cerebral artery as against 83% for umbilical artery. The sensitivity was 71% for middle cerebral artery versus 44% for umbilical artery.

Conclusion

Growth restricted fetuses with normal flow velocimetry are at a lower risk than those with abnormal velocimetry in terms of poor Apgar score and neonatal intensive care admission. The average birth weight of the neonates with abnormal Doppler studies was lower as compared to that of neonates with normal velocimetry. Thus middle cerebral artery doppler indices were a better predictor for fetal outcome in IUGR when compared with umbilical artery in terms of sensitivity and predictive value.     

胎儿脐动脉多普勒信号分数维测定的应用价值

目的探讨脐动脉多普勒信号分数维测定在产科的应用价值。方法将１０４例２２～４１周的妊娠妇女分为正常妊娠组（５９例）、病理妊娠组（４５例）。用彩色多普勒超声检测脐动脉并获得多普勒信号,将此信号以音频形式输入计算机中,对此信号进行处理并计算分数维。结果正常妊娠组分数维１．８３±０．０３,病理妊娠组分数维异常率明显高于正常妊娠组（Ｐ＜０．００１）;比较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）,结果提示在病理妊娠组中,分数维异常率明显高于Ｓ／Ｄ比值异常率。同时,经直线相关分析,分数维与孕周有明显相关性（ｒ＝０．２６６）。结论分数维是反映脐动脉血流复杂性的参数,较Ｓ／Ｄ比值更能客观地反映病理状态下脐动脉血流的变化。因此,分数维是一项较好的脐动脉血流参数,值得进一步研究、推广     

Umbilical and uteroplacental blood flow velocity waveforms in pregnancies with fetal growth retardation

A 2 MHZ pulsed Doppler ultrasound was used to record blood flow velocity waveforms (FVW) in the umbilical and arcuate arteries of 129 singleton pregnancies where intra-uterine growth retardation (IUGR) was suspected at routine ultrasound screening in the 32nd week of gestation. All patients were examined once a fortnight, between 32nd week and delivery, the results presented being from the final examination before delivery. The FVW were characterized by the pulsatility index (PI). Sixty-six of the 129 newborns were growth-retarded at delivery (birthweight less than or equal to mean--2SD of the general population). Of the IUGR cases, 56% had an abnormal PI (greater than or equal to mean + 2SD of normals) in the umbilical artery and 47% in the arcuate artery. Significant relationships were found between abnormal umbilical artery PI and both IUGR (p less than 0.001) and operative delivery for fetal distress (ODFD) (p less than 0.001). No such relationship was found between abnormal PI in the arcuate artery and either IUGR or ODFD. Four placenta waveform classes (PWC), reflecting the FVW on either side of the placenta, are presented and compared with the outcome of pregnancy. The data show the umbilical artery FVW to be a good predictor of IUGR and intra-uterine fetal distress, whereas the arcuate artery FVW appears to have low predictive value for the above conditions.     

Correlation between biomagnetic and Doppler findings of umbilical artery in fetal growth restriction

OBJECTIVE: To assess the value of biomagnetic recordings of the umbilical artery over Doppler ultrasound screening in order to predict complications of impaired uteroplacental blood flow in fetuses with intrauterine growth restriction (IUGR). METHODS: Our study population included 11 IUGR preeclamptic (34-37-weeks gestation; birth weight 1969 +/- 129 g) and 19 normal pregnancies (34-37-weeks gestation; birth weight 3195 +/- 229 g). Umbilical artery Doppler ultrasound waveform measurements were expressed in terms of pulsatility index (PI). Biomagnetic signals (waveforms) recorded from the IUGR umbilical artery were expressed in terms of magnetic power spectral amplitudes. RESULTS: In all cases, the frequency band considered was 2 to 7 Hz. The spectral amplitudes were low (mean: 117+/-24 fT/ radical Hz) in most (90.9%) IUGR pregnancies and high (mean: 224+/-37 fT/ radical Hz) in most normal pregnancies (89.5%). There was a statistically significant difference between normal and IUGR pregnancies with respect to spectral amplitudes (p < 0.0001), Doppler PI (p < 0.0005), pH (p < 0.0005) and Apgar score (p < 0.0005). Multiple linear regression analysis revealed an influence of PI, pH and Apgar scores on the biomagnetic values (ANOVA: p < 0.0005). CONCLUSION: Our data imply that biomagnetic values of the umbilical artery flow could prove to be a helpful method for the evaluation of fetal well being especially in pregnancies complicated with preeclampsia and growth restriction.     

彩色多普勒超声监测正常妊娠和胎儿生长迟缓孕妇及胎儿血液…

目的应用彩色多普勒超声监测子宫－胎盘儿血液循环方法测定１５０例中、晚期妊娠妇女「其中正常８９例,胎儿生长迟缓５８例,妊娠合并慢性肾功能不良及ＩＵＧＲ３例」的脐动脉,脐静脉及宫动脉的时间平均血流速度和血流量等血流动力学变化,并监测母血雌三醇,胎盘泌乳素、血栓素Ｂ２和６ｋｅｔｏ－ＰＧＦ１ａ水平。     

Fetal blood flow in diabetic pregnancy

Forty pregnant diabetic women were examined with combined Doppler and real-time ultrasound. The volume blood flow in the fetal aorta and umbilical vein was higher and the pulsatility index (PI) in the aorta lower in the early third trimester, as compared with a reference group. Near term, the umbilical artery PI was higher in diabetic than in non-diabetic pregnancies, indicating a higher placental vascular resistance in the former group. The high umbilical artery PI occurred in fetuses who later developed distress in labor. Therefore, a high umbilical artery PI cannot be considered characteristic of diabetic pregnancy, although fetal distress might be more common in diabetic pregnancy. In addition, a high aortic volume flow was found in those fetuses who later develop distress in labor. This might be an expression of an early compensatory mechanism for increased placental vascular resistance. No specific flow variation was observed for any White class, or in association with hypertension or non-optimally regulated diabetes. The blood flow variables in growth-accelerated fetuses were comparable to those found in fetuses with normal weight. Since fetal distress might be more common in diabetic pregnancy, ultrasonic fetal blood flow measurements are recommended for antenatal fetal surveillance.     

Validity of umbilical artery blood velocimetry in the prediction of intrauterine growth retardation and fetal compromise

In a prospective longitudinal investigation, the validity of umbilical artery velocimetry in the detection of IUGR and fetal compromise was calculated in a group of 105 patients. With the help of pulsed Doppler ultrasound, measurements were performed from a menstrual age of 15 weeks onwards till term. The pulsatility index was calculated. The sensitivity, specificity, likelihood ratio and post test probability were determined with regard to the ability to predict IUGR and fetal compromise. The sensitivity in the detection of IUGR was 44.4%, the post test probability was 32.4%. For the prediction of fetal distress a sensitivity of 77.8% and a post test probability of 40.1% was calculated. In a selected group of high-risk patients (IUGR or PIH) the post-test probability was 77.6%. It seems clear that umbilical artery velocimetry is not useful as a screening tool for IUGR, but it has some potential to predict fetal distress.     

The value of Doppler ultrasound in the diagnosis and management of twin-to-twin transfusion syndrome

To evaluate the efficiency of the Doppler examination of umbilical arterial blood flow for the antenatal diagnosis and the monitoring of fetal condition during intrauterine treatment of twin-to-twin transfusion syndrome (TTTS), we studied 33 pairs of twins including 5 TTTS cases. In all cases umbilical arterial blood flow was examined by Doppler ultrasound and pulsatility index (PI) was calculated as umbilical arterial impedance. In twins with TTTS, PI of the recipient was outside the normal range and the difference of PI was greater than +0.5. In discordant twins without TTTS and concordant twins, the PI was within the normal range and the difference of PI ranged from −0.5 to +0.5. In 2 cases these findings were found before the appearance of fetal hydrops. In 2 TTTS cases transmaternal digitalization prevented the development of hydrops in the recipient. The difference of PI decreased with improvement in the fetal condition, and vice versa. Our data suggested that, in cases with TTTS, Doppler examination of umbilical arterial blood flow was effective in predicting fetal hydrops. Doppler was also very useful for monitoring the fetal condition during intrauterine treatment.     

胎儿脑及脐动脉血流检测的临床意义

应用彩色多普勒超声，检测正常妊娠妇女４８例（正常妊娠组），妊高征患者３４例（妊高征组），妊高征合并胎儿生长迟缓（ＩＵＧＲ）５４例（ＩＵＧＲ组）儿大脑中动脉及脐动脉血流速波，计算血流的收缩末期峰值与舒张末期峰值的比值、脉搏指数、阻力指数。     

Recent Advances in the Use of Doppler Waveform Indices in the Antenatal Assessment of Intrauterine Growth Retardation

Summary: Doppler ultrasound has been advocated as a useful tool to evaluate pregnancies with intrauterine growth retardation (IUGR). However, many previous studies have used smallness for gestational age (SGA) at birth to define IUGR. The ability of Doppler ultrasound to predict SGA, neonatal morphometric indices of wasting such as a low ponderal index, and perinatal morbidity is reviewed. Doppler assessment of the umbilical and uteroplacental vasculatures were inferior to ultrasound measurements of fetal size in the prediction of SGA. In low risk fetuses, umbilical artery waveform indices were of limited value in the prediction of neonatal morphometric indices of wasting. Within a group of high risk fetuses, Doppler assessment of the umbilical artery and, in particular, the middle cerebral and aortic vessels, were useful in predicting fetuses with neonatal wasting. Similar findings were noted in the prediction of perinatal morbidity. The review confirms the usefulness of umbilical artery Doppler waveform indices in the antenatal assessment of IUGR. Whilst preliminary studies appear to suggest that Doppler waveform indices of the middle cerebral and aortic vessels may confer an additional advantage in the antenatal assessment of IUGR, randomized controlled trials evaluating their effect on perinatal outcome and studies on the reproducibility of these indices need to be carried out before their widespread introduction into obstetric practice.     

Umbilical vein blood flow measurement in nonimmune hydrops fetalis

Twenty-five measurements of fetal umbilical vein blood flow were performed in 22 cases of nonimmune hydrops fetalis using real-time and pulsed Doppler duplex ultrasound. The umbilical vein diameter, blood velocity, and blood flow in fetuses with hemoglobin Bart's hydrops fetalis were usually higher than those in fetuses with hydrops fetalis from other causes. Umbilical vein blood flow measurement appears to be an effective technique for differentiating hemoglobin Bart's from non-Bart's hydrops in this series. This hemodynamic characteristic of umbilical vein blood flow may be helpful in determining the etiology of nonimmune hydrops fetalis.