Test Code RHEV RHG Eval Post Partum

Important Note

Flow Cytometry is REQUIRED to determine fetal bleed / RhIg dose

If the gestation is 20 weeks or less
And a single fetus
One (1) vial of RhIg will be dispensed
For TWINS / MULTIPLE gestation 20 weeks or less: Flow Cytometry is REQUIRED to determine fetal bleed / RhIg dose

Specimen and Container/Tube

Whole Blood EDTA pink top

Rejection Criteria

Specimen will be rejected due to missing handwritten collection information (date MM/DD/YY or MM/DD/YYYY, time, and initials).

Clinical Indications

This test evaluates the need for Rh immunoglobulin (RhIG) postpartum. The percentage of fetal hemoglobin RBCs is measured by flow cytometry (or Kleihauer-Betke) and can be used to calculate the fetal hemorrhage in the maternal circulation. The standard of care is to administer RhIG when Rh-negative mother delivers Rh-positive newborn. At least ONE vial of RhIG should be given even if testing is negative for fetal bleeding because a very small amount of fetal blood, even below the detection limit of these tests, can still potentially cause Rh sensitization in a Rh-negative mother.

To calculate the RhIG dose:

Multiply the "% Fetal cells" detected in maternal circulation by the maternal blood volume to estimate the size of the fetal bleed.

Example: If 1.0% fetal cells are detected in maternal circulation by the maternal blood volume is 5000 mL, the estimated bleed size is 50 mL (0.01 x 5000 mL).

2. To determine the number of full-sized (300 µg) RhIG vials to order, divide the estimated fetal bleed volume (in mL) by 30.

3. Round the result to the nearest whole number, applying the following rule:

If the decimal portion is less than 0.5, round down and add one vial.
If the decimal portion is 0.5 or greater, round up and add one vial.
Example: For a 50 mL bleed: 50 / 30 = 1.67. Round up to 2 and add one vial, resulting in a total of 3 RhIG vials.

A calculation tool is available https://uchicagomedlabs.testcatalog.org/csatalogs/367/files/7215

Test Components

ABO, Rh,
ASC

Methodology

Column Agglutination (Gel) for ABO/Rh and Screen.

Test Includes

ABO, Rh,
ASC

Specimen Type

Whole Blood EDTA pink top

Preferred Volume

6 mL

Test Usage

This test evaluates the Rhogam needs of the mother postpartum.

Container/Tube

Pink top, EDTA

NOTE: All blood bank samples must have HAND WRITTEN collection information on the label to be accepted (date MM/DD/YY or MM/DD/YYYY, time, and initials).

Specimen Minimum Volume

2 mL

Day(s) Performed

24/7

STAT DAY(S) AND TIME(S) PERFORMED

N/A

Method Name