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Test Code FMB Fetomaternal Bleed, Flow Cytometry, Blood

Reporting Name

Fetomaternal Bleed,Flow Cytometry,B

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Determining the volume of fetal-to-maternal hemorrhage for the purposes of recommending an increased dose of the Rh immune globulin

Method Name

Flow Cytometry


Ordering Guidance


This test is for the detection of fetal bleed, it should not be used to detect the hereditary persistence of fetal hemoglobin (HPFH) or to detect fetal maternal hemorrhage in a mother with HPFH. For HPFH diagnosis, order HBEL1 / Hemoglobin Electrophoresis Evaluation, Blood.

 

NY State Clients: testing is available; order FMBNY / Fetomaternal Bleed, New York, Blood.



Shipping Instructions


Specimen must arrive within 5 days (preferably 24-72 hours) of collection.



Specimen Required


Container/Tube: Lavender top (EDTA)

Specimen Volume: Full tube

Collection Instructions:

1. Do not centrifuge.

2. Invert several times to mix blood.

3. Send whole blood specimen in original tube. Do not aliquot as aliquoting into or out of a sample tube can adversely affect test results.


Specimen Type

Whole Blood EDTA

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole Blood EDTA Refrigerated (preferred) 5 days
  Ambient  5 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject
Clotted blood Reject

Reference Values

≤1.5 mL of fetal red blood cells in normal adults

Interpretation

Greater than 15 mL of fetal red blood cells (RBC) (30 mL of fetal whole blood) is consistent with significant fetomaternal hemorrhage (FMH).

 

A recommended dose of Rh immune globulin (RhIG) will be reported for all specimens. One 300 mcg dose of RhIG protects against a FMH of 30 mL of D-positive fetal whole blood or 15 mL of D-positive fetal RBC. Recommended standard of practice is to administer RhIG within 72 hours of the fetomaternal bleed for optimal protective effects. The effectiveness of RhIG decreases beyond 72 hours post exposure but may still be clinically warranted. This assay has been validated out to 5 days post collection.

Day(s) Performed

Monday through Sunday

Report Available

Same day/1 day

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

88184-Flow cytometry, cell surface, cytoplasmic

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FMB Fetomaternal Bleed,Flow Cytometry,B 75308-7

 

Result ID Test Result Name Result LOINC Value
28204 Mother's Rh 10331-7
28202 Fetal-Maternal Bleed 55730-6
28203 Rh Immune Globulin 55731-4
4058 Remarks 48767-8