Fetal hemodynamics evaluated by Doppler velocimetry in the second half of pregnancy

The objective of our study was to assess fetal hemodynamics by Doppler velocimetry during the second half of pregnancy. We carried out a longitudinal study on 33 normal fetuses between the 22nd and 38th weeks of gestation. Doppler velocimetry was performed in the aorta, suprarenal (SRA) and infrarenal (IRA) segments, middle cerebral artery (MCA) and umbilical artery (UA), on the basis of fetal peak systolic velocity (SV), end-diastolic velocity (DV) and resistance index (RI). We used a sample volume of 1 mm, a wall filter of 50 to 100 Hz, a 5 degrees to 19 degrees insonation angle in the MCA and UA, and below 60 degrees in the SRA and IRA. Between the 22nd and 38th weeks of gestation, SV and DV increased in all fetal arteries (p<0.05), but SV decreased in the UA from 52.5 to 46.2 cm/s between the 34th and 38th gestational weeks (p<0.05). The RI was unchanged in the SRA and throughout most of the gestational weeks in the IRA (p>0.05), but decreased from 0.69 to 0.56 in the UA (p<0.05). In the MCA, it decreased from 0.85 to 0.75 between the 26th and 38th gestational weeks (p<0.05). In conclusion, the volume of blood flow in the fetal organs necessary for their development is related to increased SV and DV and to decreased RI. The Doppler velocimetry measurements for normal fetuses could be compared with those for fetuses in high-risk pregnancies.     

Fetal cerebral blood flow redistribution in late gestation: identification of compromise in small fetuses with normal umbilical artery Doppler.

OBJECTIVE: To evaluate the role of middle cerebral artery Doppler in small fetuses during the late third trimester. DESIGN: Prospective observational study of structurally normal fetuses with an estimated fetal weight < 5th percentile for gestation. Perinatal outcome was determined using a structured datasheet sent to each referring obstetrician. SUBJECTS: Structurally normal fetuses at 35 or more weeks of gestation referred during a 2-year period to the fetal growth clinic of a regional fetal medicine unit in North London. Fetuses with aneuploidy and/or major structural abnormalities were excluded. METHODS: Umbilical artery and middle cerebral artery (MCA) Doppler waveforms were recorded and considered abnormal if above 95th or below 5th percentiles, respectively. Amniotic fluid was considered reduced if the maximum vertical cord-free pool was < 2 cm. The placenta was considered mature if the Grannum grade was II or III. The head circumference (HC)/abdominal circumference (AC) ratio was considered abnormal if > 95th percentile for gestation. Fetal growth, amniotic fluid, biophysical profile score and umbilical artery Doppler were used to advise the referring obstetrician about fetal well-being and he/she independently decided both the timing and mode of delivery. RESULTS: Forty-seven fetuses fulfilled the entry criteria. Thirty-four (72%) demonstrated normal umbilical artery Doppler waveforms. Sixteen (34%) demonstrated middle cerebral artery redistribution, of which nine (56%) had normal umbilical artery Doppler waveforms. MCA blood flow redistribution was associated with an increased incidence of cesarean delivery and need for neonatal admission. Of all gray-scale parameters, an elevated HC/AC ratio has the strongest association with MCA blood flow redistribution (15/16 vs. 1/31; P < 0.01). CONCLUSIONS: MCA Doppler may be a useful tool to assess the health of small fetuses in the late third trimester. Redistribution may occur in the presence of normal umbilical artery Doppler and should be suspected when the HC/AC ratio is elevated.     

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.     

正常中孕胎儿大脑中动脉血流参数比值的正常值范围

目的 确定正常中孕胎儿大脑中动脉血流参比值的正常值范围。方法 应用二维超声、彩色多普勒能量图及脉冲多普勒技术对215例16-31孕周正常胎儿头围、体重及大脑中动脉血流参数进行检测。结果 正常中孕胎儿每分钟单位体重大脑中动脉的最大速度及平均速度随孕周的增加而降低;每分单位头围大脑中动脉的最大速度及平均速度在中孕期间变化小。结论 本研究为多普勒超声早期预测胎儿高动力循环状态提供了理论依据。     

Prenatal color Doppler sonographic evaluation of nuchal encirclement by the umbilical cord

PURPOSE: The aim of this study was to assess whether Doppler flow velocimetry of the fetal middle cerebral and umbilical arteries is affected by nuchal encirclement by the umbilical cord (nuchal cord) in the prenatal period. PATIENTS AND METHODS: The position of the fetal umbilical cord was assessed on color Doppler sonography in pregnant women who were referred to our radiology department between September 14, 1998, and January 14, 2000. Pulsatility and resistance indices and the ratio of peak systolic blood flow velocity to diastolic velocity of the umbilical arteries and middle cerebral arteries of all fetuses were prospectively obtained with Doppler flow velocimetry. The fetuses were categorized into 2 groups: group 1 consisted of fetuses without sonographic evidence of nuchal cord and group 2 of fetuses with sonographic evidence of nuchal cord. The results were statistically analyzed with independent-groups t test. A p value of less than 0.05 was considered significant. RESULTS: During the study period, 230 pregnant women underwent sonographic examination of the fetus, and 68 fetuses were delivered. The sonographic examinations were performed at 24-41 weeks' menstrual age. Of the 46 fetuses in group 1, 1 fetus had nuchal cord at delivery; of the 22 fetuses in group 2, 4 did not have nuchal cord at delivery. The sensitivity of color Doppler sonography in detecting nuchal cord was 95% (18 of 19 fetuses), the specificity was 92% (45 of 49), the negative predictive value was 98% (45 of 46), and the positive predictive value was 82% (18 of 22). No statistically significant differences in middle cerebral artery or umbilical artery Doppler flow velocimetry values were detected between the 2 groups. CONCLUSIONS: Color Doppler sonography is a sensitive and specific method of diagnosing nuchal cord, but fetal middle cerebral artery and umbilical artery Doppler flow velocimetry values are not affected by the presence of nuchal cord in the prenatal period.     

Fetal arterial Doppler studies in twin-twin transfusion syndrome.

This cross-sectional study investigates the circulatory profile of the donor and recipient fetuses in pregnancies with twin-twin transfusion syndrome manifested by acute polyhydramnios during the second trimester of pregnancy. Doppler investigations of the umbilical arteries and of the fetal descending thoracic aortas and middle cerebral arteries were performed in both fetuses of 27 pregnancies with twin-twin transfusion syndrome at 18 to 25 (mean, 21.7) weeks' gestation. Significant differences from normal values were increased umbilical artery pulsatility index and decreased aortic mean velocity in both donor and recipient fetuses, decreased middle cerebral artery pulsatility index in recipients and decreased middle cerebral artery mean velocity in donors. Increased umbilical artery pulsatility index in some donor and recipient fetuses may be the consequence of abnormal placental development and polyhydramnios-related compression, respectively. Doppler findings in the fetal circulation are compatible with hypovolemia in the donor and hypervolemia with congestive heart failure in the recipient.     

Single umbilical artery: a Doppler flow velocity study of four cases.

We measured the pulsatility index of the umbilical artery in four fetuses identified as having a single umbilical artery. A pulsed color Doppler ultrasound machine was used and measurements were performed at 4-week intervals following the first diagnosis of single umbilical artery (week 22-34). The pulsatility index was derived from the mean of five consecutive measurements at the umbilical insertion of the cord, taking care to obtain the Doppler signal with an incidence angle between +45 degrees and -15 degrees. All measurements were taken during periods of fetal inactivity.The pulsatility index at 22, 26, 30, 34 and 38 weeks in these pregnancies did not differ significantly from the mean values registered in normal pregnancies. The four women gave birth to babies of normal weight: two were healthy, one suffered from bladder extrophy and hemispondyly, the other had bilateral dilatation of the renal pelves, megalocystis, megalourethra and an imperforate anus.     

First-trimester uteroplacental and fetal blood flow velocity waveforms in normally developing fetuses: a longitudinal study.

Our objectives were to obtain a complete overview of uteroplacental and fetal hemodynamics early in pregnancy and to record flow velocity waveforms in the vitelline artery using color Doppler equipment. Flow velocity waveforms were recorded in 18 uneventful pregnancies between 6 and 16 weeks of gestation. Doppler recordings were made of the left and right uterine and spiral arteries from 6 weeks of gestation onwards. Recordings of c the umbilical artery, fetal aorta and fetal cerebral arteries started in weeks 7, 8 and 9, respectively. Where possible, the vitelline arteries were also recorded. The resistance and pulsatility indices and 95% confidence intervals for predictions were calculated.For the uterine and spiral arteries, characteristics of the waveforms were assessed. The resistance index of both uterine and spiral arteries gradually decreased with advancing pregnancy. For the umbilical artery, aorta and cerebral artery, the earliest possible Doppler recordings and characteristics of the waveforms were established. The pulsatility index of the umbilical arteries and fetal aorta showed a sharp decrease towards the 16th week. The pulsatility index of the fetal cerebral artery showed only a mild decrease towards week 16. In a longitudinal analysis, there were significant changes of the resistance and pulsatility indices for each patient. In the vitelline artery, recordings were possible in eight out of 18 fetuses, and only in weeks 7 and 8 of gestation. The pulsatility index showed a wide range and was not dependent on menstrual age.Knowledge of the normal flow velocity waveforms in the maternal uteroplacental and fetal circulations early in pregnancy may lead to a better understanding of physiological mechanisms.     

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。     

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.     

Middle cerebral artery Doppler in severe intrauterine growth restriction.

OBJECTIVE: To examine longitudinal changes in middle cerebral artery blood flow assessed by Doppler in severely growth restricted fetuses. METHODS: Eighteen structurally normal singleton pregnancies complicated by suspected intrauterine growth restriction were monitored by serial measurement of the pulsatility index of the middle cerebral artery over 7 to 72 days. Outcome measures included indication for delivery, umbilical venous pH and admission to and length of stay in neonatal intensive care. RESULTS: Thirteen fetuses demonstrated severe intrauterine growth restriction based on subsequent birth weights being below the 2.5th centile, two had intrauterine growth restriction (birth weights between the 2.5th and 5th centiles), and three had birth weights between the 5th and 50th centiles. The middle cerebral artery pulsatility index showed rapid and sharp changes between examinations in those severely growth restricted fetuses which required delivery before 34 weeks. This pattern was not obvious in severely growth restricted fetuses delivered after 34 weeks, or in those less severely growth restricted, regardless of the gestation at delivery. Changes in middle cerebral artery pulsatility index contributed to the decision to deliver in three cases. The middle cerebral artery pulsatility index demonstrated greater variation in those fetuses with cord pHs of less than 7.25. The length of stay in neonatal intensive care decreased with increasing gestational age and birth weight. CONCLUSIONS: The difference in the pattern of change in middle cerebral artery pulsatility index in intrauterine growth restricted fetuses may be a reflection of maturity in addition to the degree of fetal compromise. The decision to deliver was multifactorial. The middle cerebral artery pulsatility index only influenced the decision to deliver when changes in other parameters were evident.     

Changes in the aortic and pulmonary diameters in a fetus with hypoplastic left heart syndrome

We diagnosed hypoplastic left heart syndrome in a 26-week-old fetus using fetal echocardiography. Color Doppler ultrasonography was helpful for evaluating the structural abnormalities. The diameters of the aorta and the pulmonary artery were measured periodically from 26 to 38 weeks of gestation. Aortic diameter was below the normal range throughout gestation. The diameter of the pulmonary artery was normal at 26 weeks of gestation but gradually dilated and was abnormally dilated after the 36th week of gestation. Here we discuss the cause of enlarged pulmonary artery in fetal hypoplastic left heart syndrome.     

Cardiac blood flow studies in fetuses with homozygous alpha-thalassemia-1 at 12-13 weeks of gestation.

OBJECTIVE: Fetuses affected by homozygous alpha-thalassemia-1 develop anemia as early as the first trimester. Our objective was to study hemodynamic indices in affected fetuses at 12-13 weeks of gestation to determine whether these would be useful in the prediction of anemia. DESIGN: Prospective observational study. SUBJECTS: Women referred before 14 weeks of gestation for the prenatal diagnosis of homozygous alpha-thalassemia-1. METHODS: Transabdominal and/or transvaginal Doppler sonography was performed to measure the flow velocities in the fetal ascending aorta and pulmonary artery at 12-13 weeks. The Doppler indices were compared between those that were subsequently confirmed to be affected by homozygous alpha-thalassemia-1 and those that were unaffected. RESULTS: Between June 1997 and April 1998, 60 eligible women were recruited. Doppler examination was successful in 58 fetuses. Of these, 22 were subsequently confirmed to be affected by homozygous alpha-thalassemia-1. The diagnosis was made by chorionic villus sampling and DNA analysis in two affected fetuses and by cordocentesis and hemoglobin evaluation in 20 affected fetuses. Hemoglobin concentrations could be measured in ten fetuses and these ranged from 4 to 8 g/dl. The affected fetuses had significantly higher peak velocities at the pulmonary valve and ascending aorta and a larger inner diameter of the pulmonary valve than that in unaffected fetuses. The total cardiac output was increased by one-third in affected fetuses and was mainly due to an increase of the right-side cardiac output. CONCLUSION: In the early stage of anemia, the fetus responds mainly by increasing its right-side cardiac output. However, there is extensive overlap of the values of cardiac output between the affected and the unaffected fetuses, precluding its use in the prediction of anemia.     

Fetal heart rate influence on the pulsatility index in the middle cerebral artery.

In 1300 Doppler assessments performed on the fetal cerebral arteries, 5 cases of heart rate deceleration were recorded while studying the middle cerebral artery. There were 3 normal fetuses (mean menstrual age +/- standard deviation: 28.6 +/- 2.1 weeks), one growth-retarded fetus (34 weeks, menstrual age) and 1 fetus with red cell alloimmunization (27 weeks, menstrual age). The magnitude of decline in the heart rate during the deceleration ranged from 44 to 93 bpm (67 +/- 18 bpm). Pulsatility index values were calculated on 44 waveforms and correlated with the heart rate. Linear regression analysis showed a statistically significant inverse correlation between the heart rate and the pulsatility index in the middle cerebral artery of 4 fetuses. These results indicate that heart rate will affect the pulsatility index of the middle cerebral artery.     

Does the measurement of four fetal arteries provide more information than the measurement of just two arteries in prenatal Doppler sonography?

OBJECTIVE: The objective of this study was to evaluate whether the measurement of two or more fetal arteries provides more information and leads to a selection of fetuses at higher risk. DESIGN: In 244 pregnancies Doppler examinations in four fetal arteries (fetal aorta, common carotid artery, middle cerebral artery, umbilical artery) were performed. The evaluation of the results was made by means of a Doppler score for standardization and systematization. The results were divided into four groups (normal, pre-pathological, pathological, highly pathological) and the individual correlations with fetal outcome parameters were investigated. The results from measuring only two fetal arteries (the fetal aorta and middle cerebral artery) were then compared with those from all four arteries. RESULTS: Increasing pathology of the Doppler score correlated with fetal outcome parameters. The results showed that if the Doppler result in the two-vessel measurement was normal (n = 180), pre-pathological (n = 29) or highly pathological (n = 12) then measuring four vessels generally brought no additional information. However, the four-vessel measurement was of advantage in the pathological group (n = 23) because it selected the high-risk fetuses (30.4%), as categorized by outcome. CONCLUSIONS: Differentiating between several degrees of pathology is important for the estimation of fetal risk. In cases of pathological Doppler findings, the measurement of more than two vessels is important in order to select fetuses at increased risk.     

Nifedipine therapy for preterm labor: effects on placental, fetal cerebral and atrioventricular Doppler parameters in the first 48 hours.

OBJECTIVE: To assess the effect of nifedipine tocolysis on Doppler parameters of the uterine, umbilical and fetal middle cerebral arteries and atrioventricular valves in the first 48 h of therapy. METHODS: Doppler waveforms of uterine, umbilical and middle cerebral arteries and both atrioventricular valves were measured from 28 pregnant women and fetuses prior to and during nifedipine therapy for preterm labor. Maternal and fetal heart rates (FHR), maternal systolic and diastolic blood pressure, and the Doppler pulsatility index (PI) of the uterine, umbilical and middle cerebral arteries were measured. The cerebroplacental ratio (middle cerebral artery PI/umbilical artery PI) was calculated. The total time velocity integrals (TVIs) of tricuspid and mitral valves and their E- and A-wave peak velocity ratio (E/A) were measured. Friedman repeated-measures analysis of variance was used to compare the variables before and after nifedipine therapy. If significant differences were found, Wilcoxon's signed ranks test was used to analyze the difference between the two variables. A P-value of < 0.05 was considered significant. RESULTS: Nifedipine maintenance was associated with a significant decline in maternal systolic and diastolic blood pressure after 24 h, while maternal heart rate and FHR were unaffected. The uterine artery PI had decreased significantly at 24 and 48 h, while the umbilical artery PI did not change significantly. The middle cerebral artery PI had decreased significantly at 24 and again at 48 h. A significant fall in the cerebroplacental Doppler ratio was maintained beyond 24 h. The mean E/A values, TVIs and TVI x FHR values at 24 and 48 h were unchanged from the baseline values. CONCLUSIONS: Nifedipine maintenance tocolysis is associated with a significant decline in uterine artery and middle cerebral artery Doppler indices 24 h after the first dose. Fetal cardiac diastolic function is unaffected and the significant redistribution observed after 24 h is likely to be attributable to altered cerebral blood flow.     

Fetal echocardiography and color Doppler flow imaging: the Rotterdam experience.

The adjunctive role of Doppler color flow mapping in the evaluation of cardiac structures and function was studied in 440 normal fetuses between 17 and 22 weeks of gestation (median, 20 weeks) and in 73 fetuses with suspected congenital heart disease between 16 and 38 weeks of gestation (median, 28 weeks). Flow through atrioventricular and arterial valves was generally easy to identify and identification was successful in approximately 90% of the normal fetuses. Flow in the pulmonary veins and through the foramen ovale was visualized in approximately 60% of normal cases. In the group with suspected congenital heart disease, Doppler color flow imaging provided additional information on both cardiac structure and function in 34 fetuses, on function alone in 13 fetuses and on structure alone in 20 fetuses. No additional information was collected in six fetuses.     

四腔心切面联合三血管气管切面彩色多普勒超声在孕11~13+6周胎儿严重先天性心脏畸形筛查中的应用价值

目的探讨四腔心切面联合三血管气管切面彩色多普勒超声在孕11~13⁺⁶周胎儿严重先天性心脏畸形筛查中的应用价值。 方法选择2018年1月至12月在四川省妇幼保健院行孕期检查的9756例孕妇,分别于孕 11~13⁺⁶周及孕16~24周进行胎儿心脏超声检查。采用四腔心切面联合三血管气管切面彩色多普勒超声对孕11~13⁺⁶周胎儿筛查心脏畸形,采用标准化胎儿超声心动图筛查孕16~24周胎儿心脏畸形,并对分娩后所有新生儿及引产胎儿进行随访。 结果9756例胎儿孕11~13⁺⁶周超声筛查发现心脏畸形38例（51.4%,38/74）,其中非严重心脏畸形5例（14.2%,5/35）,严重心脏畸形33例（84.6%,33/39）。出生或引产后诊断先天性心脏畸形74例,其中严重先天性心脏畸形39例,非严重心脏畸形35例。 结论运用四腔心切面联合三血管气管切面彩色多普勒超声能筛查出大部分严重胎儿心脏畸形,可为临床咨询、预后提供及时有力的证据。     

Longitudinal changes in the ductus venosus, cerebral transverse sinus and cardiotocogram in fetal growth restriction.

OBJECTIVE: To evaluate the changes in flow velocity waveforms in the transverse cerebral sinus in growth-restricted fetuses and to correlate these changes with (1) flow velocity waveforms in the ductus venosus and (2) changes in computerized analysis of the fetal cardiotocogram. DESIGN: Fetuses between 22 and 37 weeks' gestation with an estimated fetal weight below the fifth centile were included in this prospective longitudinal study. Doppler measurements of the umbilical artery, descending aorta, middle cerebral artery, transverse cerebral sinus and ductus venosus were recorded. Fetal heart rate was analyzed by a computer system according to the Dawes-Redman criteria. RESULTS: We measured a significant correlation between pulsatility index in the cerebral transverse sinus and in the ductus venosus over the study period and at delivery. There was a negative correlation between these indices and short- and long-term variability of the fetal heart rate. There was a parallel increase in pulsatility in the ductus venosus and the transverse cerebral sinus. These changes were inversely correlated with fetal heart rate variability and preceded fetal distress. CONCLUSION: Cerebral venous blood flow in IUGR fetuses may be a useful additional investigation to discriminate between fetal adaptation and fetal decompensation in chronic hypoxemia.     

Treatment of D alloimmunization in pregnancy with plasmapheresis and intravenous immune globulin: case report

The prevalence of D alloimmunization occurs between 0.15% and 0.4%. The anti-D can cross the placenta and cause hemolysis and fetal anemia. At present, a Doppler study of the middle cerebral artery allows the monitoring of the degree of fetal anemia. The treatment in cases of moderate to severe anemia in fetuses of less than 34–35 weeks of gestation is intrauterine transfusion via cordocentesis. However, with high titers of anti-D, in the absence of fetal anemia it is possible to modulate the maternal immune response by plasmapheresis and intravenous immunoglobulin administration. We present a case report of an Rh(D) alloimmunized pregnancy treated with plasmapheresis followed by intravenous immunoglobulin administration. We performed a caesarean section at 31 weeks, 5 days of gestation. The hemoglobin at birth was 13.8 g/dl and hematocrit 40.8%. Intrauterine transfusion was not necessary.