What test is used to screen fetomaternal hemorrhage?
What test is used to screen fetomaternal hemorrhage?
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.
What is the Kleihauer-Betke test used for?
Background: In maternal trauma, the Kleihauer-Betke (KB) test has traditionally been used to detect transplacental hemorrhage (TPH), so that Rh-negative women could receive appropriate Rh immune prophylaxis.
How is fetomaternal hemorrhage calculated?
The amount of fetal maternal hemorrhage is calculated by multiplying the percent fetal cells by 50. This calculation assumes that maternal blood volume is 5000 mL or 50 dL. This product is then divided by 30, which is the volume of fetal whole blood neutralized by a single vial of RhIg (300 ug dose).
What is FMH test?
Test description. The purpose of this test is to determine if the mother has experienced a placental bleed which would allow fetal blood cells to enter maternal circulation. This test is particularly important when an Rh negative mother has an Rh positive fetus.
When do you use KB test?
In massive trauma, the KB test may be utilized primarily, without the preliminary use of the screening rosette test. The Kleihauer Betke test is utilized to determine if there is fetal blood in maternal circulation, with a threshold of 5 mL.
How is a KB test performed?
When a sample of maternal blood is exposed to an acid, the maternal hemoglobin washes away, while the fetal hemoglobin remains intact. After this acid elution, the slide is washed, stained, and examined under the microscope.
How is Kleihauer Betke test calculated?
V. Interpretation
- Calculate Maternal Blood Volume (ml) = (Pre-pregnant weight in kg) x 70 ml/kg x. (1.0 + (0.5 x weeks gestation/36)) –
- Calculate Fetal Whole Blood (ml) = (Fetal Cell Count/Maternal Cell Count) x. Maternal Blood Volume.
- Rh Immune Globulin (RhoGAM) Dose. Give 300 ug per 30 ml fetal whole blood or 15 ml pRBC.
What happens fetomaternal hemorrhage?
1 Massive fetomaternal hemorrhage (FMH) involves fetal blood loss into the maternal circulation of more than 150 ml or otherwise more than half the fetal blood volume. 2 Large bleeds can be a cause of intrauterine death in up to 0.04% of all births.
How is KB test performed?
The Kleihauer Betke test is utilized to determine if there is fetal blood in maternal circulation, with a threshold of 5 mL. The rosette test is performed by incubating the Rh-negative maternal venous whole blood sample with anti-Rho(D) immune globulin.
How long does a KB test take?
Kleihauer – Betke Test
| Test Name: | Kleihauer – Betke Test |
|---|---|
| Testing Schedule: | 24 hours, 7 days/week |
| Turn Around Time: | STAT: NA |
| Routine: 4-6 hours | |
| Collection Information: | No special patient preparation is required. Obtain specimen by standard collection procedures. Cord blood is not acceptable for this procedure. |
How is fetal hemoglobin tested?
A fetal hemoglobin test (Hgb electrophoresis) measures the level of fetal hemoglobin (Hemoglobin F or HbF) in the blood of infants and children. It can also be measured in adults, though is more typically needed for diagnoses of congenital illnesses in children.