Fetal Cell Counting as a Guide to Prevention of Rh Sensitization

Clayton, Everett M.; Birdwell, E. D.; GREGORY, M. G.

doi:10.1111/j.1537-2995.1973.tb04472.x

Cited by 3 publications

(2 citation statements)

References 2 publications

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“…Both over‐ and underestimation of FMH have been reported [ 15, 22–25], but most of the studies report the tendency of the Kleihauer‐Betke test to overestimate FMH. Variables potentially contributing to both under‐ and overestimation are listed in Table II.…”

Section: Quantitative Tests For Measuring Fetal Rbcs In Maternal Circmentioning

confidence: 99%

Detection of fetomaternal hemorrhage

Kim

Makar

2012

American J Hematol

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The prevention of Rhesus D alloimmunization through Rh immune globulin (RhIg) administration is the major indication for the accurate detection and quantification of fetomaternal hemorrhage (FMH). In the setting of D incompatibility, D-positive fetal cells can sensitize the D-negative mother, resulting in maternal anti-D alloantibody production. These anti-D alloantibodies may lead to undesirable sequelae such as hemolytic disease of the newborn (HDN). Since the widespread adoption of FMH screening and RhIg immunoprophylaxis, the overall risk of Rh alloimmunization and infant mortality from HDN has substantially decreased. The rosette screen, the initial test of choice, is highly sensitive in qualitatively detecting 10 mL of fetal whole blood in the maternal circulation. As the screen is reliant on the presence of the D antigen to distinguish fetal from maternal cells, it cannot be used to detect FMH in D-positive mothers or in D-negative mothers carrying a D-negative fetus. The Kleihauer-Betke acid-elution test, the most widely used confirmatory test for quantifying FMH, relies on the principle that fetal RBCs contain mostly fetal hemoglobin (HbF), which is resistant to acid-elution whereas adult hemoglobin is acid-sensitive. Although the Kleihauer-Betke test is inexpensive and requires no special equipment, it lacks standardization and precision, and may not be accurate in conditions with elevated F-cells. Anti-HbF flow cytometry is a promising alternative, although its use is limited by equipment and staffing costs. Hematology analyzers with flow cytometry capabilities may be adapted for fetal cell detection, thus giving clinical laboratories a potentially attractive automated alternative for quantifying FMH. Am. J. Hematol. 87:417-423, 2012. V

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Section: Quantitative Tests For Measuring Fetal Rbcs In Maternal Circmentioning

confidence: 99%

Detection of fetomaternal hemorrhage

Kim

Makar

2012

American J Hematol

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“…38 Shepard and colleagues also confirmed prior observations that the proportion of HbA and HbF in newborns' RBCs varies widely and that the percentage of HbF in newborns' RBCs correlates better with the gestational age than with birth weight. 39,40 Clayton and colleagues [41][42][43][44] evaluated the optimal technical conditions for performing the K-B acidelution assay. They observed that the citric acid-phosphate buffer must be prepared at precisely pH 3.2 for optimal elution, which was performed after adding methylene blue to the citric acid-phosphate buffer at 50ºC and cooling it to 37ºC for a 15-minute elution.…”

Section: Quantitative Methods For Measuring Fetal Rbcs In Maternal Blood Samples K-b Acid-elution Assaymentioning

confidence: 99%

Laboratory methods for Rh immunoprophylaxis: a review

Sandler¹,

Sathiyamoorthy

2010

Immunohematology

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The recommended dose of Rh immune globulin for postpartum Rh immunoprophylaxis is based on an estimation of the volume of the fetomaternal hemorrhage, if any, measured as the percent of fetal RBCs in a sample of the D-mother's blood. Laboratory methods for distinguishing fetal from maternal RBCs have been based on their different blood types (D+ versus D-) or predominant hemoglobin content (hemoglobin F versus hemoglobin A). We conducted a review of the medical literature describing laboratory methods for detecting and quantifying fetal RBCs in maternal blood samples. We also used data collected for the College of American Pathologists Fetal RBC Detection Surveys to determine which laboratory methods are used currently in hospitals in the United States. The rosette screen is used widely for identifying D-mothers who may require additional doses of Rh immune globulin for postpartum immunoprophylaxis. As the rosette screen targets the D antigen, it is not suitable for detecting a fetomaternal hemorrhage in D+ mothers or when the D type of the fetus or newborn is D-or unknown. The acid-elution (Kleihauer-Betke) assay is a sensitive laboratory method for quantifying a fetomaternal hemorrhage, but it is tedious, often inaccurate, and difficult to reproduce. Flow cytometry, using anti-D or antihemoglobin F reagents, offers a more precise quantification of fetal RBCs in maternal blood. However, flow cytometry services for this function are available in relatively few hospital laboratories in the United States because of logistic and fiscal impediments.

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Breakthrough Rhesus Sensitization in Spite of Anti‐d Gamma Globulin Given Throughout Pregnancy

Baker

1975

Medical Journal of Australia

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Fetal Cell Counting as a Guide to Prevention of Rh Sensitization

Cited by 3 publications

References 2 publications

Detection of fetomaternal hemorrhage

Detection of fetomaternal hemorrhage

Laboratory methods for Rh immunoprophylaxis: a review

Breakthrough Rhesus Sensitization in Spite of Anti‐d Gamma Globulin Given Throughout Pregnancy

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