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PubMed1986

Have Liley charts outlived their usefulness?

Fetal blood and amniotic fluid samples were obtained fetoscopically from 59 rhesus-isoimmunized pregnancies at 18 to 25 weeks' gestation. Fetal hemoglobin was measured and amniotic fluid optical density deviation at a wavelength of 450 nm determined. Two sets of normal reference values for optical density at 450 nm and fetal hemoglobin at 16 to 36 and 16 to 25 weeks were established from 475 amniotic fluid and 153 fetal blood samples obtained from pregnancies not complicated by fetal hemolysis. As expected, there was a significant linear correlation between the degree of fetal anemia and the amniotic fluid optical density at 450 nm in rhesus-isoimmunized pregnancies. However, the values of optical density at 450 nm were widely scattered, thereby limiting their ability to predict accurately the severity of disease in these second-trimester pregnancies. In 25 of the patients, the value of optical density at 450 nm was determined at 6 to 16 days before fetoscopy. The severity of fetal anemia could not be predicted by the trend in optical density at 450 nm. These data suggest that the only reliable method to determine the severity of rhesus isoimmunization in the second trimester of pregnancy is the direct measurement of fetal hemoglobin.

Amniotic Fluid↗
PubMed1989

Pulsed Doppler flow-velocity waveforms in the prediction of fetal hematocrit of the severely isoimmunized pregnancy.

We previously reported a significant relationship between the hematocrit levels of anemic fetuses and information derived from ultrasonographic and Doppler flow-velocity waveforms. In this study we prospectively tested two formulas for the prediction of hematocrit values, by use of gestational age, presence or absence of hydrops, and Doppler indices. Although one of the two formulas predicted hematocrit values significantly, the only component of the formula that made a significant contribution was fetal hydrops. We conclude that currently available fetal Doppler measurements are unable to be applied in the prospective prediction of hematocrit values in anemic fetuses of isoimmunized pregnancies.

Blood Flow Velocity↗
PubMed1990

Cordocentesis for rapid karyotyping.

Pure fetal blood was obtained by cordocentesis in 101 fetuses of 96 patients at 15 to 38 weeks' gestation. Rapid karyotype was obtained within 2 to 4 days by fetal lymphocyte culture. Chromosomal abnormality was detected in 12 (11.9%) fetuses. Abnormal karyotype was found in 5 of 44 fetuses with structural malformations, 3 of 13 fetuses with intrauterine growth retardation or oligohydramnios, 1 of 3 fetuses with nonimmune hydrops fetalis, 2 (one monozygotic set) of 10 discordant twins, 1 of 12 isoimmunized gestations, none of 8 cases with advanced gestational-maternal age, and none of 6 immune thrombocytopenia cases. This suggests that rapid karyotype should be obtained in all cases of fetal structural malformations, intrauterine growth retardation, and nonimmune fetal hydrops, and may be obtained incidentally in isoimmunized pregnancies and discordant twins to assist in clinical management.

Adult↗
PubMed1995

The relationship between peak velocity in the fetal descending aorta and hematocrit in rhesus isoimmunization.

OBJECTIVE: To correlate the peak velocity in the fetal descending aorta, as measured by pulsed Doppler ultrasound, with fetal hematocrit values assessed by funipuncture in pregnancies complicated by rhesus isoimmunization. METHODS: One hundred twelve consecutive funipunctures were performed on 33 rhesus-negative gravidas of 21-36 weeks' gestation (median 30). Doppler flow, corrected for angle, was measured on the fetal descending aorta with pulsed Doppler equipment immediately before funipuncture. Differences between observed peak velocities and the calculated gestational age-dependent upper confidence limits (delta peak velocities) were compared with corresponding differences between observed hematocrits and the calculated lower confidence limits (delta hematocrits), and a regression analysis on the above paired difference values was performed. In addition, the correlation coefficient between delta peak velocities and delta hematocrits was calculated for the first procedure per pregnancy only. RESULTS: The mean peak aortic velocity of anemic fetuses was higher than that of unaffected fetuses (P < .001); delta peak aortic velocities correlated negatively with delta hematocrits (r = -0.66, P < .001). The correlation coefficient between delta peak aortic velocities and delta hematocrits for the first procedure peer pregnancy only was r = -0.72 (P < .001). Prediction of fetal anemia by Doppler using gestational age-dependent 95% confidence limits was possible with positive and negative predictive values of 73 and 66%, respectively. CONCLUSION: Peak aortic velocity, a noninvasive assessment of fetal anemia, may be used as an additional test for monitoring pregnancies complicated by rhesus isoimmunization. However, the limited predictive capacity hampers its clinical usefulness.

Anemia↗
PubMed1998

Maternal sickle cell anemia and neonatal isoimmunization.

OBJECTIVE: To study the risk of alloimmunization in pregnant women with sickle cell disease (SCD) and of isoimmunization in their offspring. METHOD: Thirty mothers with SCD were studied and their 35 neonates (group 1) were compared with 538 infants of mothers without hemoglobinopathies (group 2). RESULT: Six mothers with SCD developed alloantibodies. There was no correlation with maternal age (P = 0.6), parity (P = 0.18) or blood transfusions (P = 0.4). The risk of alloimmunization by transfusion was 20%. Six neonates were isoimmunized, a higher incidence than in group 2 (P = 0.02; relative risk 3.07). Five had ABO incompatibility and only one had anti-c isoimmunization. All had reticulocytosis, jaundice and required phototherapy, one developed anemia but none required blood transfusion. CONCLUSION: Although alloimmunization was common in mothers with SCD and isoimmunization in their offspring, it was rarely due to non-ABO alloantibody. There was no significant neonatal morbidity.

Adult↗
PubMed1991

Absence of hyperinsulinemia in isoimmunized fetuses treated with intravascular transfusion.

We serially sampled blood from fetuses of five severely isoimmunized pregnancies at the time of each intrauterine intravascular transfusion and at birth. We were unable to demonstrate either an elevation in the plasma insulin/glucose ratio or a relationship between the insulin/glucose ratio and hemoglobin concentration at any time period. Plasma total glutathione concentration, however, decreased dramatically from the initial to the second transfusion (323 +/- 114 to 43 +/- 9 ng/ml; t = -5.06, p less than 0.01). We speculate that intrauterine transfusion may modify or prevent the previously reported fetal pancreatic beta-cell hyperplasia and hyperinsulinemia associated with isoimmunization by decreasing red blood cell hemolysis and thereby circulating glutathione.

Anemia↗
PubMed1990

Is intrauterine transfusion associated with diminished fetal growth?

Studies in animal models and human pregnancies suggest that severe fetal anemia and/or replacement of fetal with adult blood result in decreased pH, increased base deficit, and hyperlactacidemia. Similar changes have been noted in growth-retarded, nonanemic fetuses, and we therefore hypothesized that isoimmunized fetuses requiring intrauterine transfusions might have diminished growth. We longitudinally studied growth patterns in 17 isoimmunized fetuses by noting biparietal diameter and head and abdominal circumference measurements at each transfusion. The distributions of these measurements above and below the 25th, 50th, and 75th percentiles derived from our general obstetric population were compared at the initial transfusion and the last ultrasonogram performed before delivery. Birth weights also were noted and their distribution around the 25th, 50th, and 75th percentiles was compared to the expected distribution. For each ultrasonographic parameter, the distribution of measurements at the last ultrasonogram before delivery was not significantly different from the distribution at the initial ultrasonogram. The birth weight distribution also was not significantly different than the expected distribution. Thus we were unable to demonstrate slowing of fetal growth in our severely isoimmunized pregnancies.

Anemia↗
PubMed1990

Severe hemolytic disease of the newborn due to anti-c.

Two cases of severe hemolytic disease of the newborn due to c-isoimmunization are presented. Both women were multiparous, had previous blood transfusion and high maternal titers of anti-c (1:1024 and 1:4036, respectively).

Adult↗
PubMed1988

Serial fetal blood sampling for the management of pregnancies complicated by severe rhesus (D) isoimmunization.

Fifty-one pregnancies complicated by rhesus (D) isoimmunization have been managed by serial fetal blood sampling between 17 and 36 weeks gestation as an alternative to amniocentesis for delta OD453 measurements. In 36 pregnancies where the fetus was shown to be rhesus (D) positive and both measurements were made before any intrauterine fetal transfusions, the delta OD453 value gave misleading predictions on 13 of 63 occasions (21%). Fetal haematocrit estimations provided a direct assessment of the haemopoietic compensation occurring, but fetal bilirubin and albumin concentrations did not correlate directly with disease severity. It is proposed that pregnancies complicated by severe isoimmunization can be more precisely managed by serial fetal blood sampling for haematocrit estimation than amniocentesis for delta OD453 measurement thus avoiding unnecessary intervention or delayed treatment.

Female↗
PubMed1990

Prediction of fetal anemia by measurement of the mean blood velocity in the fetal aorta.

In 68 red blood cell isoimmunized pregnancies the mean velocity of blood in the fetal aorta was measured by pulsed Doppler ultrasonography, and the fetal hemoglobin concentration was determined in blood samples obtained by cordocentesis. The values were compared to reference ranges of mean aortic velocity and hemoglobin for gestation, which were determined from 218 218 pregnancies that were not complicated by fetal hemolysis. In the red blood cell isoimmunized pregnancies there was a significant positive correlation between the aortic mean velocity and the hemoglobin deficit for the nonhydropic fetuses and a significant negative correlation between these two parameters for the hydropic fetuses.

Anemia↗
PubMed1994

Umbilical artery Doppler flow-velocity waveforms and fetal acid-base balance in Rhesus-isoimmunized pregnancies.

Pulsed Doppler blood-flow velocity waveforms in the umbilical arteries, as well as blood gases, hematocrit, and lactate concentration in umbilical venous blood, were examined in 21 patients undergoing 49 cordocentesis, 34 of which were followed by fetal blood transfusion into the umbilical vein. The aim of the study was to evaluate the correlations, if any, between the Doppler indices from the umbilical artery (pulsatility index, resistance index, systolic/diastolic ratio) and the blood gas values (pO2, pCO2, O2 content, pH) and lactate content in the umbilical vein. The only correlation confirmed in this study was in the subgroup of anemic fetuses undergoing fetal blood transfusion, where correlation existed between A/B and the initial O2 content (r = -0.41, p < 0.02). We conclude that, in Rhesus-isoimmunized pregnancies, in contrast to other pregnancies, a close correlation does not exist between the Doppler indices in the umbilical artery and the fetal blood gas values.

Acid-Base Equilibrium↗
PubMed1991

Enhanced sensitization after cordocentesis in a rhesus-isoimmunized pregnancy.

It has been suggested that the optical density at 450 nm may be an unreliable predictor of the severity of fetal anemia in the midtrimester of pregnancy; therefore fetal blood sampling, rather than amniotic fluid evaluation, should be performed in all isoimmunized pregnancies with elevated maternal antibody titers in the midtrimester. Potential complications of such an approach are discussed and an alternative plan of management is offered.

Adult↗
PubMed1985

Ultrasound in congenital intracranial haemorrhage secondary to isoimmune thrombocytopaenia.

Three cases of congenital intracranial haemorrhage, diagnosed post-natally by ultrasound, are presented. The ultrasound findings of intracranial haemorrhage secondary to thrombocytopaenia are discussed. The haematomas were partly organised at birth and the ventricular systems were dilated in two cases. This type of haemorrhage is a different entity from post-natal intracranial haemorrhage in the preterm infant.

Cerebral Hemorrhage↗
PubMed1998

[Management of Rhesus isoimmunization. Viewpoint of the obstetrician].

Although rare, severe forms of Rhesus isoimmunization are still observed. Early diagnosis and treatment with intrauterine transfusions allow an 80% survival rate. Anti-D alloimmunizations usually result from missed prophylaxis with anti-D serum at delivery, thus underlying the need for a rigorous application of this prophylaxis.

Blood Transfusion, Intrauterine↗