脉冲多普勒超声对胎儿不同妊周脐带及脑循环动态变化的研究

目的，探讨不同妊周胎儿脐血流及脑血流的变化规律。方法，对４２２例妊娠２１～４２周正常产妇，用脉冲多普勒超声测量其胎儿脐带动脉（ＵＡ）、大脑中动脉（ＭＣＡ）之ＲＩ（阻力指数）与ＰＩ（搏动指数）。结果与结论，ＲＩ与ＰＩ的变化高度一致（ｒ＝０．９７８）（ｐ＜０．００１）。ＵＡ两指数在妊娠２１周时最高，此后逐渐下降至足月（Ｐ＜０．００１）。ＭＣＡ两指数从２１周起先缓慢上升，２９周时达高峰，此后迅速下降至足月（ｐ＜０．００１）。ＵＡ的ＲＩ、ＰＩ与ＭＣＡ的ＲＩ、ＰＩ之比值，从妊娠２１周起迅速下降，２９～３４周间维持较低水平，以后缓慢上升，到妊娠足月时仍明显低于妊娠２１周时水平（Ｐ＜０．００１）。     

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

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

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

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

彩色多普勒超声观察不同孕周正常胎儿动脉血流的价值

目的：探讨不同孕周胎儿肾动脉（RA）、脐动脉（UA）、大脑中动脉（MCA）血流参数的变化情况,确定正常胎儿RA、UA、MCA血流参考值,并分析RA、UA、MCA血流参数与孕龄的关系。方法选取2013年1～12月在该院行产前检查的185例孕周为4～41周的正常单胎孕妇为研究对象,采用彩色多普勒超声测量胎儿 RA、UA、MCA的阻力指数（RI）、搏动指数（PI）、收缩期峰值流速（PS）及收缩期峰值流速与舒张末期流速比值（S/D）。结果随着孕周的增加,胎儿RA、UA、MCA中PS值显著增加,而RA、UA中RI、PI、S/D值显著减少。经相关性分析可知,RA、UA、MCA中RI、PI、S/D与孕周呈负相关性（P＜0．05）,而RA、UA、MCA中PS与孕周呈正相关性（P＜0．05）。结论应用彩色多普勒测量不同孕周胎儿RA、UA、MCA血流动力学参数能有效了解胎儿颅脑循环、胎盘循环及全身血流循环状态。通过建立正常胎儿血流参数参考范围可为超声预测胎儿宫内生长情况提供参考依据。     

Cardiovascular hemodynamics and umbilical artery N-terminal peptide of proB-type natriuretic peptide in human fetuses with growth restriction.

OBJECTIVE: To test our hypothesis that human fetal N-terminal peptide of proB-type natriuretic peptide (NT-proBNP) secretion is increased in proportion to the severity of fetal cardiovascular compromise in intrauterine growth restriction. METHODS: This prospective cross-sectional study consisted of 42 growth-restricted fetuses who underwent Doppler ultrasonographic examination of cardiovascular hemodynamics within 7 days before delivery. Group 1 fetuses (n = 13) had normal umbilical artery (UA) velocimetry. Group 2 fetuses (n = 15) had abnormal UA and normal ductus venosus (DV) velocimetry. In Group 3 fetuses (n = 14), both UA and DV velocimetries were abnormal. At delivery, an UA blood sample was obtained for assessment of NT-proBNP. Normal values for UA NT-proBNP were determined in 49 neonates (control group) with uncomplicated pregnancy and delivery. RESULTS: Group 3 fetuses demonstrated greater (P < 0.05) UA and descending aorta pulsatility indices (PIs) and greater DV, left hepatic vein (LHV) and inferior vena cava PIs for veins (PIVs) than fetuses in Groups 1 and 2. Weight-indexed cardiac outputs and ventricular ejection forces were similar among the groups. Group 3 fetuses had higher (P < 0.05) UA NT-proBNP concentration than fetuses in Groups 1 and 2. In the control group, the 95(th) percentile value of UA NT-proBNP was 518 pmol/L. In Group 3, 13/14 neonates demonstrated abnormal UA NT-proBNP levels. The corresponding incidences were 4/13 and 7/15 in Groups 1 and 2. Significant positive correlations were found between UA, DV and LHV PIVs and UA NT-proBNP concentrations. CONCLUSION: In human fetal growth restriction, increased cardiac afterload and pulsatility in DV blood velocity waveform pattern are associated with elevated UA NT-proBNP concentrations.     

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

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

应用能量多普勒检测正常胎儿脑动脉的血流动力学

目的确定胎儿正常脑动脉血流参数的正常值. 方法用能量多普勒及脉冲频谱多普勒检测165例胎龄16～40周胎儿的大脑中动脉(MCA)、大脑前动脉(ACA)、大脑后动脉(PCA)、后交通动脉(PCoA)的收缩期速度(Vs)、舒张期速度(Vd)、搏动指数(PI)、阻力指数(RI)、收缩期/舒张期速度比值(S/D). 结果脑动脉血流速度参数两侧对比无显著性差异(P＞0.05),MCA、ACA、PCA的血流速度与妊娠周数存在显著正相关(P＜0.01),即随妊娠周数增加而增快,脑动脉的PI、RI与妊娠周数也存在显著相关(P＜0.01).在妊娠末期(36～40周),脑动脉的血流速度增至最大,而PI、RI、S/D则下降至最低. 结论本文的数据可作为胎儿脑动脉血流动力学正常值的参考,并可用于临床监测胎儿的生长发育.     

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.     

Abnormal fetal cerebral and umbilical Doppler measurements in fetuses with intrauterine growth restriction predicts the severity of perinatal morbidity

PURPOSE: This prospective study was performed to determine if the ratio of the middle cerebral artery (MCA) S/D ratio (ratio of peak systolic blood flow velocity to diastolic velocity) to the umbilical artery (UA) S/D ratio (MCA/UA S/D ratio) predicts the degree of neonatal morbidity in fetuses suspected of having intrauterine growth restriction (IUGR). METHODS: Sixty-one fetuses were identified prospectively by sonography as having an estimated fetal weight below the 10th percentile for gestational age. The 61 fetuses underwent Doppler sonography in the third trimester and then were stratified into 3 groups based on the MCA/UA S/D ratio: group A, MCA/UA S/D ratio > 1.0 (controls; n = 37); group B, MCA/UA S/D ratio < or = 1.0 (intracerebral blood flow redistribution; n = 16); and group C, reversed or absent UA diastolic flow (n = 8). Outcome variables assessed included gestational age at delivery, birth weight, UA pH, mode of delivery, respiratory distress syndrome requiring intubation, and intracranial hemorrhage. RESULTS: The mean MCA/UA S/D ratios in groups A and B were 1.69 + /- 0.61 and 0.59 + /- 0.24, respectively (p < 0.01). The mean gestational ages at delivery for groups A, B, and C were 34.7, 33.2, and 29.0 weeks, respectively. The mean birth weights were below the fifth percentile for age for groups B and C and significantly related to the severity of abnormal Doppler findings (p < 0.01) after correction for age. Mean UA pHs were 7.25 + /- 0.01, 7.19 + /- 0.01, and 7.14 + /- 0.13 for groups A, B, and C, respectively, with significant differences between groups A and B (p < 0.05) and groups A and C (p < 0.05). Respiratory distress syndrome and intracranial hemorrhage were not associated with abnormal Doppler findings after correction for gestational age. The interval between the abnormal Doppler examination and delivery (p < 0.001) and the occurrence of fetal distress requiring cesarean section (p < 0.001) were significantly related to the severity of Doppler findings. CONCLUSIONS: In fetuses with suspected IUGR, abnormal MCA/UA S/D ratios are strongly associated with low gestational age at delivery, low birth weight, and low UA pH. Abnormal MCA/UA S/D ratios are also significantly associated with shorter interval to delivery and the need for emergent delivery.     

Doppler application in the delivery timing of the preterm growth-restricted fetus: another step in the right direction.

This article provides an opinion on a study of relationships between umbilical artery (UA) Doppler, ductus venosus (DV) Doppler, fetal heart rate variation, and perinatal outcome in preterm, intrauterine growth-restricted (IUGR) fetuses published in the same issue of this journal by Bilardo and coworkers. Recent evidence on venous Doppler surveillance in preterm IUGR fetuses was also reviewed and discussed in the context of the study with a special emphasis on delivery timing. A search was conducted through MEDLINE and eight articles with similar inclusion criteria and reporting format of outcomes were identified. Numbers for perinatal mortality, intraventricular hemorrhage, respiratory distress syndrome, bronchopulmonary dysplasia and necrotizing enterocolitis (NEC) were extracted for cases where Doppler status was recorded in an identical format. Proportional distribution of outcomes was compared for fetuses with normal DV Doppler velocimetry, absent or reversed UA end-diastolic velocity (UA A/REDV), elevated DV Doppler index (abnormal DV) and absence or reversal of atrial velocity in the DV (DV-RAV). A total of 320 fetuses with normal and 202 with elevated DV Doppler indices were extracted. Of these fetuses, 101 with UA A/REDV only and 34 with DV-RAV were identified. Perinatal mortality was 5.6% (16/282) with normal DV, 11.9% (12/101) with UA A/REDV, 38.8% (64/165) with abnormal DV and 41.2% (7/17) with DV-RAV. With the exception of NEC, all complications were significantly more frequent with abnormal DV. With normal venous Doppler neonatal deaths account for most of the perinatal mortality, while with abnormal DV stillbirths and neonatal mortality are similar contributors to the significantly increased perinatal mortality. In conclusion, UA Doppler is a placental function test that provides important diagnostic and prognostic information in preterm IUGR. DV Doppler effectively identifies those preterm IUGR fetuses that are at high risk for adverse outcome (particularly stillbirth) at least 1 week before delivery, independent of the UA waveform. Relationships between perinatal outcome, arterial and venous Doppler status and gestational age require ongoing observational research effort. Randomized management trials are necessary to verify that delivery timing based on venous Doppler will impact on outcome in preterm IUGR.     

Relationship between arterial and venous Doppler and perinatal outcome in fetal growth restriction.

OBJECTIVE: The aim of this investigation was to assess the relationship between abnormal arterial and venous Doppler findings and perinatal outcome in fetuses with intrauterine growth restriction (IUGR). METHODS: Doppler velocimetry of the umbilical artery (UA), middle cerebral artery (MCA), inferior vena cava (IVC), ductus venosus (DV) and free umbilical vein was performed in 121 IUGR fetuses with a UA pulsatility index (PI) > 2 SD above the gestational age mean and subsequent birth weight < 10th centile for gestational age. Groups based on the last Doppler exam were: 1 = abnormal UA-PI only (n = 42, 34.7%), 2 = MCA-PI > 2 SD below the gestational age mean (= 'brain sparing') in addition to abnormal UA-PI (n = 29, 24.0%), 3 = DV or IVC peak velocity index (PVIV) > 2 SD above the gestational age mean and/or pulsatile UV flow (n = 50, 41.3%). Z-scores (delta indices) were calculated for Doppler indices. Perinatal mortality, respiratory distress (RDS), bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), circulatory failure and umbilical artery blood gases were recorded. RESULTS: Absence or reversal of umbilical artery end-diastolic flow was observed in 4 (9.5%) of fetuses in group 1, 10 (34.5%) fetuses in group 2 and 41 (82%) fetuses in group 3. A low middle cerebral artery pulsatility index was found in 39 (78%) fetuses in group 3. Multiple regression analysis with gestational age at delivery, delta indices and cord artery blood gas as independent parameters and individual perinatal outcomes as dependent variables was performed. In this analysis the association was strongest with gestational age for each complication. There were no significant differences in Apgar scores between groups. At delivery, 'brain sparing' was associated with hypoxemia and abnormal venous flows with acidemia. Perinatal mortality was highest in group 3 and stillbirth was only observed when venous flow was abnormal. All postpartum complications were more frequent in fetuses with abnormal venous flows. The only statistically significant relation between Doppler indices and outcome was the association between abnormal ductus venosus flow and fetal death (r2 = 0.24, P < 0.05). CONCLUSION: Growth restricted fetuses with abnormal venous flow have worse perinatal outcome compared to those where flow abnormality is confined to the umbilical or middle cerebral artery. In fetuses with low middle cerebral artery pulsatility, venous Doppler allows detection of further deterioration. While abnormal venous flows can be significantly associated with fetal demise, gestational age at delivery significantly impacts on all short-term outcomes.     

Is fetal cerebral vascular resistance affected by the presence of nuchal cord(s) in the third trimester of pregnancy?

OBJECTIVE: To assess whether fetal cerebral vascular resistance is affected by the presence of nuchal cord(s) in the third trimester. METHODS: A set of 115 patients with well-established dates and singleton, appropriate for gestational age (GA), non-anomalous fetuses with nuchal cord(s) diagnosed with prenatal color Doppler imaging, between 28 and 41 weeks and 115 controls matched for GA, were studied. Patients with hypertension, diabetes and autoimmune conditions were excluded. Doppler indices were obtained from the umbilical artery (UA) and the fetal middle cerebral artery (MCA) upon initial diagnosis of the nuchal cord. RESULTS: Of 115 GA-matched pairs of pregnancies, 103 fetuses had a single nuchal cord and 12 a double nuchal cord. No significant differences were noted in patient age, gravidity, parity, sonographically estimated fetal weight (SEFW), and growth centile at ultrasonographic diagnosis. Mean UA systolic/diastolic ratio (S/D) was 2.28 +/- 0.32 and 2.36 +/- 0.33 (P = 0.03) and UA resistance index (RI) 0.55 +/- 0.06 and 0.57 +/- 0.06 (P = 0.02) among study and controls, respectively. Mean fetal MCA S/D and RI did not differ significantly between the two groups (fetal MCA S/D 5.01 +/- 1.28 and 5.04 +/- 1.71 (P = 0.86), and mean fetal MCA RI 0.78 +/- 0.06 and 0.78 +/- 0.05 (P = 0.88)). No significant differences were noted in GA at delivery, incidence of meconium-stained amniotic fluid, birth weight, mode of delivery, neonatal gender, 1 and 5 minute Apgar scores, or UA pH and base excess, between study and control patients. CONCLUSION: Fetal cerebral vascular resistance is not affected by the presence of nuchal cord(s) in the third trimester of pregnancy.     

Qualitative venous Doppler flow waveform analysis in preterm intrauterine growth-restricted fetuses with ARED flow in the umbilical artery--correlation with short-term outcome.

OBJECTIVE: The aim of this retrospective study was to examine the significance of severe Doppler waveform abnormalities in the ductus venosus (DV) and the umbilical vein (UV) for the prediction of adverse outcomes in very preterm growth-restricted fetuses with absent or reversed end-diastolic flow in the umbilical artery (UA) at 24-34 weeks of gestation. METHODS: Seventy-four fetuses with intrauterine growth restriction (IUGR) and absent or reversed end-diastolic (ARED) flow in the UA at 24-34 weeks of gestation, which were delivered before 34 weeks' gestation, were examined. Absent or reversed flow during atrial contraction (a-wave) in the DV and pulsatile flow in the UV were examined to predict severe perinatal outcomes (stillbirth, neonatal death, perinatal death, acidemia, 5 min Apgar < 7, intraventricular hemorrhage and elevated nucleated red blood cell counts at delivery). RESULTS: Twelve (16.2%) perinatal deaths, of which eight were stillbirths (10.8%), and two (2.7%) neonatal deaths occurred among 74 fetuses. Logistic regression analysis confirmed that abnormal DV Doppler waveforms (R2 = 0.57, P < 0.001) together with gestational age at delivery (R2 = 0.57, P < 0.001) showed the strongest association with perinatal death, whereas only gestational age was significantly related to neonatal death (R2 = 0.67, P < 0.05). Abnormal DV Doppler waveforms (R2 = 0.86, P < 0.001) and gestational age (R2 = 0.49, P < 0.05) were strongly associated with adverse outcome (including stillbirth, perinatal death or neonatal death). Abnormal venous Doppler flow patterns performed better in the prediction of fetal or perinatal demise than did ARED flow or brain sparing. CONCLUSION: Abnormal venous Doppler waveforms in preterm IUGR fetuses with ARED flow are strongly related to adverse fetal and perinatal outcomes before 32 weeks of gestation. The possible benefit of prolonging these pregnancies can only be evaluated in a prospective randomized study.     

Computerized fetal heart rate analysis, Doppler ultrasound and biophysical profile score in the prediction of acid-base status of growth-restricted fetuses.

OBJECTIVE: To investigate the performance of non-stress test (NST), computerized fetal heart rate analysis (cCTG), biophysical profile scoring (BPS) and arterial and venous Doppler ultrasound investigation in the prediction of acid-base status in fetal growth restriction. METHODS: Growth-restricted fetuses, defined by abdominal circumference < 5(th) percentile and umbilical artery (UA) pulsatility index > 95(th) percentile, were tested by NST, cCTG, BPS, and UA, middle cerebral artery (MCA), ductus venosus (DV) and umbilical vein (UV) Doppler investigation. The short-term variation (STV) of the fetal heart rate was calculated using the Oxford Sonicaid 8002 cCTG system. Relationships between antenatal test results and cord artery pH < 7.20 were investigated, using correlation, parametric and non-parametric tests. RESULTS: Fifty-six of 58 patients (96.6%) received complete assessment of all variables. All were delivered by pre-labor Cesarean section at a median gestational age of 30 + 6 weeks. The UA pulsatility index (PI) was negatively correlated with the cCTG STV (Pearson correlation - 0.29, P < 0.05). The DV PI was negatively correlated with the pH (Pearson correlation - 0.30, P < 0.02). The cCTG mean minute variation and pH were not significantly correlated (Pearson correlation 0.13, P = 0.34). UV pulsations identified the highest proportion of neonates with a low birth pH (9/17, 53%), the highest number of false positives among patients with an abnormal BPS, abnormal DV Doppler and a STV < 3.5 ms, and also stratified false negatives among patients with an equivocal or normal BPS. Abnormal DV Doppler correctly identified false positives among patients with an abnormal BPS. cCTG reduced the rate of an equivocal BPS from 16% to 7.1% when substituted for the traditional NST. Elevated DV Doppler index and umbilical venous pulsations predicted a low pH with 73% sensitivity and 90% specificity (P = 0.008). CONCLUSION: In fetal growth restriction with placental insufficiency, venous Doppler investigation provides the best prediction of acid-base status. The cCTG performs best when combined with venous Doppler or as a substitute for the traditional NST in the BPS.     

Gestational age at delivery and Doppler waveforms in very preterm intrauterine growth-restricted fetuses as predictors of perinatal mortality.

OBJECTIVE: The aim of this study was to compare gestational age at delivery and the performance of middle cerebral artery (MCA), ductus venosus (DV), and umbilical artery Doppler parameters in the prediction of perinatal mortality and morbidity in intrauterine growth-restricted (IUGR) fetuses delivered at 32 weeks or earlier. METHODS: The study population consisted of 41 patients with IUGR fetuses. Delivery occurred for maternal or fetal indications. Two-tailed chi(2) and Fisher exact tests, an independent t test, and logistic regression were used for the analysis. P < .05 was considered statistically significant. RESULTS: Gestational age at delivery ranged between 23.1 and 32 weeks (median, 27.6 weeks). There were 17 perinatal deaths. Ninety-four percent of the perinatal deaths occurred when the fetuses were delivered before 29 weeks. No fetus survived when delivered before 25 weeks. Two parameters predicted the perinatal mortality: gestational age at delivery (odds ratio, 0.52; 95% confidence interval, 0.31-0.88) and the combination of abnormal MCA peak systolic velocity + DV reversed flow (odds ratio, 10.2; 95% confidence interval, 1.8-57). For each week of pregnancy, there was a reduction in perinatal mortality of 48%. No Doppler parameters were significantly associated with perinatal morbidity. CONCLUSIONS: Gestational age at delivery and the combination of abnormal MCA peak systolic velocity + DV reversed flow in very preterm IUGR fetuses were the best parameters in predicting perinatal mortality. The decreased perinatal mortality that is found for each week IUGR fetuses remain in utero should be taken into account when a decision to deliver an IUGR fetus before 30 weeks is made.     

Doppler and biophysical assessment in growth restricted fetuses: distribution of test results.

OBJECTIVE: Multi-vessel Doppler ultrasonography and biophysical profile scoring (BPS) are used in the surveillance of growth restricted fetuses (IUGR). The interpretation of both tests performed concurrently may be complex. This study examines the relationship between Doppler ultrasonography and biophysical test results in IUGR fetuses. METHODS: Three hundred and twenty-eight IUGR fetuses (abdominal circumference < 5th percentile, elevated umbilical artery (UA) pulsatility index (PI)) had concurrent surveillance with UA, middle cerebral artery (MCA) and ductus venosus (DV) Doppler ultrasonography and BPS (fetal tone, movement, breathing, maximal amniotic fluid pocket and fetal heart rate). Patients were stratified into three groups according to their Doppler examination: (1) abnormal UA alone; (2) brain sparing (MCA-PI > 2 SD below mean for gestational age); and (3) abnormal DV (PI > 2 SD above the mean for gestational age) and BPS groups: (1) normal (> 6/10); (2) equivocal (6/10); and (3) abnormal (< 6/10). Predictions of short-term perinatal outcomes by both modalities were compared for stratification. The distribution and concordance of Doppler and BPS test results were examined for the whole patient group and based on delivery prior to 32 weeks' gestation. RESULTS: Abnormal UA Doppler results alone were observed in 109 fetuses (33.2%), brain sparing in 87 (26.5%) and an abnormal DV in 132 (40.2%). The BPS was normal in 158 (48.2%), equivocal in 68 (20.7%) and abnormal in 102 (31.1%). Both testing modalities stratified patients into groups with comparable acid-base disturbance and perinatal outcome. Of the nine possible test combinations the largest subgroups were: abnormal UA alone/normal BPS (n = 69; 21%) and abnormal DV Doppler/abnormal BPS (n = 62; 18.9%). Assessment of compromise by both testing modalities was concordant in 146 (44.5%) cases. In 182 fetuses with discordant results the BPS grade was better in 115 (63.2%, P < 0.0001). Marked disagreement of test abnormality was present in 57 (17.4%) fetuses. Of these, abnormal venous Doppler in the presence of a normal BPS constituted the largest group (Chi-square P < 0.002). Stratification was not significantly different in patients delivered prior to 32 weeks' gestation. CONCLUSION: Doppler ultrasonography and BPS effectively stratify IUGR fetuses into risk categories, but Doppler and BPS results do not show a consistent relationship with each other. Since fetal deterioration appears to be independently reflected in these two testing modalities further research is warranted to investigate how they are best combined.     

Acceleration time in the fetal middle cerebral artery during the second half of pregnancy

We made a longitudinal ultrasonographic study of 33 healthy fetuses from 22 to 38 weeks of gestation to determine the acceleration time in the middle cerebral artery (ATMCA) and its relationship with fetal cardiac output. Doppler ultrasound (US) was performed by a single observer always using the same apparatus. The Doppler tracing was obtained with a sample volume of 1 mm; placement was on the anterior middle cerebral artery, as close as possible to the skullcap. The insonation angle was kept between 5 degrees and 19 degrees and the wall filter was adjusted to a frequency of 50 to 100 Hz. The ATMCA was 40 ms at 22 and 26 weeks, 50 ms at 30 and 34 weeks and 60 ms at the 38th week. There was a significant positive correlation between gestational age and ATMCA values (r=0.45, p<0.001). The ATMCA values became significantly higher than the initial values at the 30th week of gestation (p<0.05). The ATMCA values for normal fetuses could be compared with those obtained during high-risk pregnancies; this would be useful for the detection of fetal cardiac anomalies.     

Second-trimester ductus venosus measurement and adverse perinatal outcome in fetuses with congenital heart disease.

OBJECTIVE: The purpose of this study was to determine whether Doppler velocimetry of the ductus venosus (DV) predicts adverse perinatal outcome in congenital heart disease (CHD). METHODS: We conducted a retrospective cohort study of all pregnant women undergoing fetal echocardiography for CHD in a single perinatal center during a 2-year period. We compared outcomes for fetuses having a diagnosis of CHD in the second trimester and abnormal DV Doppler velocimetric findings with those having CHD and normal DV Doppler findings. Karyotype, gestational age at delivery, fetal loss rate, and rate of termination were assessed. The referral value for an abnormal DV pulsatility index was above the 95th percentile for gestational age. Statistical analysis included the t test, Fisher exact test, and chi(2) test. RESULTS: The incidence of CHD in our population was 7%. There were 98 patients with CHD; of those, 31 had DV measurement. A total of 9 patients had an abnormal DV. Three of this group (33%) had intrauterine fetal death or perinatal death. In patients with CHD and normal DV measurements, 83% had living children versus 33% in the group with an abnormal DV (P < .05). There was no statistically significant difference in the rate of aneuploidy between the normal DV (15%) and abnormal DV (20%) groups (P = .65). The mean gestational age at delivery was similar between the normal (37.63 weeks) and abnormal (38.33 weeks) DV groups (P = .71). There was no difference in the rate of pregnancy termination. CONCLUSIONS: Abnormal second-trimester DV measurements are predictive of adverse perinatal outcome in patients with CHD, independent of karyotype or gestational age at delivery. This information may have a role in the counseling of parents with CHD.     

正常胎儿主肺动脉多普勒参数与孕周的关系

目的探讨正常胎儿妊娠中、晚期主肺动脉多普勒参数与孕周的关系。 方法将孕龄为21~40周的正常胎儿300例按照孕龄分为10组,分别为21~22^＋6周、23~24^＋6周、25~26^＋6周、27~28^＋6周、29~30^＋6、31~32^＋6周、33~34^＋6周、35~36^＋6周、37~38^＋6周和39~40^＋6周,每组30例。采用彩色超声仪测量收集正常胎儿主肺动脉多普勒参数：收缩期加速度时间（AT）、射血时间（ET）、收缩期峰值流速（PSV）、舒张期末流速（EDV）、平均流速（MV）、搏动指数（PI）和阻力指数（RI）。建立不同孕周主肺动脉多普勒参数的正常参考值,对各参数值和孕周进行相关和回归分析。 结果300例胎儿均获得满意的主肺动脉流速曲线,AT、AT/ET、PSV、EDV和MV与孕周呈线性正相关（r=0.866、0.848、0.457、0.242、0.506,P均<0.05）;PI与孕周呈线性负相关（r=-0.170,P<0.05）;ET、RI与孕周无相关性（r=0.195、-0.197,P均>0.05）。 结论正常胎儿主肺动脉多普勒参数与孕周有一定的相关性,AT、AT/ET与胎儿孕周相关性最好。     

冠状动脉扩张是胎儿生长受限预后不良的独立危险因素

目的探讨冠状动脉扩张在胎儿生长受限(FGR)中的预后评估价值。方法收集2019年1月~2020年12月我院超声诊断并出生后证实FGR胎儿73例,超声观察冠状动脉(CA)扩张、脐动脉、大脑中动脉(MCA)、静脉导管的血流频谱特征。根据胎儿妊娠结局分为预后良好组和预后不良组,比较胎儿的一般情况及胎儿不同血流异常情况,以超声变量特征建立Logistic回归模型,并绘制受试者工作特征曲线,评价Logistic回归模型对胎儿不良预后的预测价值。结果FGR胎儿预后不良组27例,预后良好组46例,在脐动脉异常、静脉导管异常、CA扩张组比较差异有统计学意义(P < 0.05),MCA异常组未见明显统计学意义(P>0.05)。Logistic回归分析显示CA扩张、脐动脉异常、静脉导管异常组OR值分别为9.715、4.956、11.291,为胎儿不良预后的独立的危险因素。以CA扩张、脐动脉异常、静脉导管异常3组变量建立的Logistic回归模型预测FGR胎儿不良预后(回归值>0.356)的曲线下面积为0.874,敏感度为81.48%,特异性为91.30%。结论冠状动脉扩张是FGR预后不良的独立的危险因素。以CA扩张、脐动脉异常、静脉导管异常3个血流异常变量建立的Logistic回归模型能够有效预测FGR不良预后。