Doppler assessment of fetal circulation in a case of fetal death.
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Adult↗
Biomedical subjects
G Mari
Publications and source records attributed to G Mari.
The effect of indomethacin on the pulsatility index of the umbilical artery in human fetuses.
Pulsed and continuous-wave Doppler ultrasonography was used to assess blood velocities in the ductus arteriosus and the pulsatility index of the umbilical artery in 20 fetuses (1 pair of twins and 18 singletons) at 23 to 33 weeks' gestation during maternal indomethacin therapy for preterm labor or polyhydramnios. There was no statistically significant difference in the pulsatility index of the umbilical artery during maternal indomethacin treatment (mean +/- SD, 1.11 +/- 0.20) when compared with baseline values (1.12 +/- 0.19) in all 20 fetuses studied. An increase in the peak systolic and diastolic blood velocities in the ductus arteriosus consistent with ductal constriction was noted in 9 fetuses. Analysis of the umbilical artery pulsatility index values before and during indomethacin in this subgroup of fetuses failed to reveal a statistically significant change (1.12 +/- 0.19 vs. 1.11 +/- 0.20). Indomethacin therapy does not influence the pulsatility index of the umbilical artery at the gestational ages studied.
Blood Flow Velocity↗
Acute fetal hemodynamic alterations after intrauterine transfusion for treatment of severe red blood cell alloimmunization.
One of the compensatory hemodynamic mechanisms seen in the anemic human fetus is an increased cardiac output. With Doppler techniques, cardiac output was measured in 21 fetuses before and immediately after 38 intrauterine transfusions for severe red cell alloimmunization. Umbilical venous pressures were measured before and after transfusion; amniotic fluid pressure was also quantitated. After subtraction of amniotic pressure, umbilical venous pressure increased by 1.7 +/- 2.8 mm Hg (p less than 0.01). Left and right ventricular output declined by 19% and 22%, respectively (p less than 0.001). Four factors are known to affect cardiac output: heart rate, cardiac contractility, preload, and afterload. Fetal heart rate and mean acceleration, a measure of myocardial contractility, were unchanged after transfusion. A calculated mean increase in the fetoplacental volume of 18% in conjunction with an increase in umbilical venous pressure would indicate that cardiac preload was increased. We propose that intravascular intrauterine transfusion leads to an increased cardiac afterload, possibly by increasing blood viscosity. The fetal heart responds to the increased afterload by a decrease in stroke volume, leading to a fall in cardiac output.
Blood Transfusion, Intrauterine↗
Prenatal diagnosis of a chest wall mass with ultrasonography and Doppler velocimetry. A case report.
An isolated mass protruding from the chest wall of the fetus was visualized by ultrasonography. Doppler velocimetry over the mass revealed low-resistance blood flow through cystic areas, implicating a highly vascular lesion. An operative delivery was performed to avoid possible rupture of the mass.
Adolescent↗
Flow velocity waveforms of the vascular system in the anemic fetus before and after intravascular transfusion for severe red blood cell alloimmunization.
Sixteen intravascular transfusions were performed in 16 anemic human fetuses. To investigate the status of the vascular system with Doppler ultrasonography before and after correction of anemia, pulsatility index values were obtained for the flow velocity waveforms of the middle cerebral artery, internal carotid artery, anterior cerebral artery, thoracic aorta, abdominal aorta, renal artery, femoral artery, and umbilical artery before and the day after the correction of anemia. The fetuses were divided into two groups: (1) fetuses with a hematocrit level between 2 and 4 SDs below the normal mean value for gestational age and (2) fetuses with a hematocrit value less than 4 SDs below the normal mean value for gestational age. No significant differences were observed in the pulsatility index values of the vessels studied before and after correction of anemia in both groups of fetuses. These data suggest that the pulsatility index cannot be used as an indicator of fetal anemia at the hematocrit values studied.
Anemia, Hemolytic, Autoimmune↗
In utero resolution of hydrops fetalis following the death of one twin in twin-twin transfusion.
A case of massive hydramnios involving a twin-twin transfusion syndrome is presented with death of the larger twin and the development of hydrops fetalis in the surviving smaller twin. The amniotic fluid volume of the surviving twin became normal and the hydrops fetalis resolved spontaneously in utero. Concomitant with the resolution of the hydrops fetalis, the umbilical cord systolic to diastolic ratio improved. At the time of delivery, the hydrops had resolved. The liveborn infant died 11 days later secondary to pulmonary hypertension and cardiorespiratory failure. Although the fetal status improved in utero, the pulmonary hypertension postdelivery resulted in neonatal death.
Adult↗
Familial protein S deficiency presenting as deep vein thrombosis occurring during pregnancy.
Subjects with congenital deficiency of protein S, a natural anticoagulant which serves as a co-factor for the antithrombotic activity of activated protein C, are at risk of thrombosis. We describe a family in which deep vein thrombosis-occurring during pregnancy in three members with abnormally low protein S activity - was the only manifestation of congenital heterozygous protein S deficiency. Early diagnosis and active treatment of protein S deficiency should be pursued in any woman with a family history of thrombosis, who is planning pregnancy.
Adult↗
Flow velocity waveforms of the umbilical and cerebral arteries before and after intravascular transfusion.
Thirteen intravascular transfusions were performed in 13 human fetuses who were anemic because of severe red-cell alloimmunization. To investigate the status of the umbilical and cerebral circulations by pulsed Doppler ultrasound, we studied the fetal middle cerebral artery (N = 13), internal carotid artery (N = 11), anterior cerebral artery (N = 11), and umbilical artery (N = 13) before, within the first 2 hours after, and the day after intravascular transfusion. The gestational age at the time of transfusion was 21-31 weeks (mean +/- SD 25 +/- 3.1). The fetal hematocrits before transfusion ranged from 12-32% (23.4 +/- 6.1), whereas the hematocrit after transfusion was between 25-42% (35 +/- 5). The net blood volume transfused (volume infused--volume removed) ranged between 7.5-31.0 mL (16.0 +/- 7.4). The hematocrit of the transfused blood varied between 68-81% (74 +/- 4). Repeated-measures analysis of variance indicated significant differences in the pulsatility index values of the four vessels studied. The same analysis indicated significant differences in the pulsatility index values at the three time points. Multiple comparison tests showed that the pulsatility index was reduced significantly immediately after transfusion for each vessel studied, but returned to pretransfusion levels by the next day. These data suggest a change in vascular impedance soon after transfusion as a consequence of direct intravascular transfusion.
Anemia↗
Effect of indomethacin on the fetal ductus arteriosus during treatment of symptomatic polyhydramnios.
Ten pregnancies with 13 fetuses complicated by symptomatic polyhydramnios were treated with indomethacin. A baseline fetal echocardiogram was obtained before therapy, repeated 24 hours after the initiation of indomethacin and then performed weekly provided that the ductus arteriosus remained patent. The mean duration of indomethacin therapy was 28.3 +/- 18.9 days. The starting dose in all patients was 25 mg orally every six hours. The ductus arteriosus was noted to constrict in four patients, with the development of tricuspid regurgitation in one. One of the constrictions occurred after 23 days of therapy. In one patient with constriction a reduction of the indomethacin dosage was not associated with constriction, while in the other three, constriction was still evident at a reduced dosage. All constrictions and the tricuspid regurgitation resolved in utero within 24 hours after discontinuation of the indomethacin. We recommend careful monitoring of the fetal ductus arteriosus when treating symptomatic polyhydramnios with indomethacin.
Ductus Arteriosus↗
Uterine blood flow velocity waveforms in pregnant women during indomethacin therapy.
Continuous-wave Doppler ultrasound was used to assess blood flow velocities and determine the pulsatility index of the uterine arteries in ten pregnant women at 23-33 weeks' gestation during indomethacin therapy for preterm labor or polyhydramnios. There was no statistically significant difference in the pulsatility index of the uterine arteries during maternal indomethacin treatment (mean +/- SD 0.85 +/- 0.29) compared with pre-treatment values (0.85 +/- 0.23). Although studies in animals have reported that indomethacin increases uterine impedance to flow, it appears that it does not affect the uterine impedance in humans.
Blood Flow Velocity↗
Doppler assessment of the renal blood flow velocity waveform during indomethacin therapy for preterm labor and polyhydramnios.
To investigate the effects of indomethacin on the human fetal renal blood flow velocity waveform, 17 fetuses whose mothers were treated for preterm labor (N = 8) or polyhydramnios (N = 9) were studied. There were five growth-retarded fetuses (all in the group with polyhydramnios), 11 normal fetuses, and one fetus with red-cell alloimmunization. The indomethacin dose in all patients was 25 mg orally every 6 hours. The gestational age of the fetuses studied varied between 24-35 weeks (mean +/- SD 29.6 +/- 2.8). The fetal renal artery was studied at its origin from the aorta before and during the first 24 hours of indomethacin therapy. Seven fetuses manifested ductal constriction. Three fetuses also manifested tricuspid regurgitation. All ductal constrictions and the tricuspid regurgitations resolved in utero after discontinuation of indomethacin. There were no significant differences in the pulsatility index values of the renal artery before and during indomethacin therapy. These results suggest that there is no change in fetal renovascular parameters detectable with pulsatility index measurements during the first 24 hours of maternal indomethacin therapy.
Ductus Arteriosus↗
Indomethacin therapy in the treatment of symptomatic polyhydramnios.
Eight gravidas with symptomatic polyhydramnios were managed with maternal indomethacin therapy. The mean gestational age at presentation was 28.6 +/- 3.5 weeks. Only patients requiring serial amniotic fluid decompressions for rapid amniotic fluid reaccumulation were enrolled in the study. An initial amniotic fluid decompression was performed and, when a second decompression was required, indomethacin was initiated. Amniotic fluid volume was measured with a para-amino hippuric acid dilution technique before and during indomethacin therapy. Fetal urine output, studied by serial bladder dimension ultrasonography, declined significantly during indomethacin therapy (P less than .05). Only one patient required further amniotic fluid decompression while on indomethacin. The mean (+/- SD) amniotic fluid volume was 1529 +/- 1070 mL after the initial amniocentesis, and was 2355 +/- 820 mL at the second amniocentesis just before indomethacin therapy. The mean amniotic fluid volume during indomethacin therapy was 1608 +/- 914 mL. We recommend initial amniotic fluid decompression followed by indomethacin therapy for the management of symptomatic polyhydramnios as an alternative to serial amniotic fluid decompressions.
Adult↗
Doppler assessment of the fetal and uteroplacental circulation during nifedipine therapy for preterm labor.
To investigate the effects of nifedipine on the human fetal circulation, 11 fetuses whose mothers were treated with nifedipine for treatment of preterm labor were studied. Maximum velocity waveforms were obtained in the middle cerebral artery (n = 8), renal artery (n = 6), ductus arteriosus (n = 8), and umbilical artery (n = 10). Transvalvular maximal velocity waveforms were obtained across the aortic (n = 11) and pulmonary (n = 7) valves. Maternal uterine arteries also were studied (n = 7). Doppler data were collected before and 5 hours after nifedipine therapy. Patients received an oral loading dose of 30 mg of nifedipine followed by a second oral dose of 20 mg 4 hours later. No significant difference in the flow velocity waveforms was found in the vessels studied 5 hours after the initial dose. These results suggest that short-term nifedipine therapy does not influence either fetal or uteroplacental circulation as evaluated with the Doppler technique.
Adolescent↗
Doppler assessment of the pulsatility index of the middle cerebral artery during constriction of the fetal ductus arteriosus after indomethacin therapy.
To investigate the effects of constriction of the ductus arteriosus on the pulsatility index of the middle cerebral artery, maximum velocity waveforms were obtained in 13 fetuses (one set of twins) whose mothers were treated with indomethacin for preterm labor (n = 9) or polyhydramnios (n = 3). Eleven of the fetuses manifested ductal constriction within 48 hours of therapy, whereas two fetuses had constriction after 1 week of therapy. Six of the 13 fetuses also manifested tricuspid insufficiency in association with constriction of the ductus arteriosus. All abnormal cardiac changes resolved in utero after discontinuation of indomethacin. No difference in the pulsatility index values of the middle cerebral artery was observed in the fetuses with ductal constriction but without tricuspid regurgitation (n = 7) when the values were compared with those obtained in absence of ductal constriction (1.87 +/- 0.37 vs. 1.88 +/- 0.33). In the fetuses that manifested both ductal constriction and tricuspid insufficiency (n = 6), the pulsatility index values in the middle cerebral artery were significantly lower in the presence of ductal constriction when compared with the values obtained in the absence of ductal constriction (2.22 +/- 0.26 vs. 1.57 +/- 0.34). These results indicate that a response to indomethacin sufficient to cause both ductal constriction and tricuspid insufficiency decreases the pulsatility index of the middle cerebral artery.
Blood Circulation↗
Doppler assessment of the pulsatility index in the cerebral circulation of the human fetus.
To determine whether the pulsatility index was similar in all cerebral vessels, 30 fetuses at 23 to 37 weeks' gestation were studied. There were 12 normal fetuses, 14 growth-retarded fetuses, and 4 fetuses that were transfused in utero because of Rh isoimmunization. The middle cerebral artery and the internal carotid artery were studied in all fetuses. The proximal anterior cerebral artery was also studied in addition to the other two vessels in 12 fetuses from the three groups. The pulsatility index was significantly higher in the middle cerebral artery than in the internal carotid artery in all three groups. The pulsatility index of the proximal anterior cerebral artery was between the values shown for the middle cerebral artery and the internal carotid artery. The pulsatility index of the proximal anterior cerebral artery was significantly different from the index for the middle cerebral artery and not significantly different from the index for the internal carotid artery. These data indicate the importance of knowing exactly which cerebral vessel is being insonated, so that the Doppler waveform can be interpreted correctly.
Carotid Artery, Internal↗
Betamethasone and the human fetal ductus arteriosus.
We used a sensitive Doppler echocardiographic technique to evaluate in utero the effects of betamethasone on the human ductus arteriosus. Transient, mild constriction of the ductus arteriosus 4-5 hours after the first injection of betamethasone occurred in two of 11 trials. The relatively mild and brief effects on the human ductus of betamethasone in usual doses are probably not clinically significant in most instances. Hence, they do not appear to contraindicate the use of glucocorticoids to promote fetal lung maturation.
Betamethasone↗
Use of stable prostacyclin analogue ZK 36 374 to treat severe lower limb ischaemia.
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Adult↗