Fetal Bleed Screen
Label Mnemonic: FBST
Epic code: LAB4367
Order form: DeGowin Blood Center Requisition
Supply order: Supply Order Form
Billing: Billing Policies
CPT code: 86905
Specimen(s):
Blood
Collection Medium:
Pink top tube 6 mL (K2-EDTA)
Minimum:
2 mL; maternal specimen
Rejection Criteria:
Specimen must be labeled with patient's first and last name and medical record number. Specimens will be rejected if information is not on the label when received.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
2 hours (upon receipt in laboratory)
Reference Range:
Negative result means no abnormal amount of fetal red blood cells has been detected in the maternal circulation.
Comments:
This test is designed to detect patients who may need more than one dose of Rhogam due to a significant fetal bleed. Maternal blood is incubated with anti-D antibodies and indicator cells prior to counting the rosettes (clumps) of RBCs. Fetal blood screening test will only be performed when fetus/infant has been typed as Rh-positive. Quantitative Fetal Hemoglobin assay will automatically be ordered if the screen is positive. If Fetal hemoglobin is elevated (≥0.3%) then additional RhoGAM is recommended as shown in the table below.

                      % HbF by Flow     Total RhoGAM (vials)
                         < 0.30%                 1
                       0.3% - 0.89%              2
                       0.9% - 1.49%              3
                       1.5% - 2.09%              4
                       2.1% - 2.69%              5
                          >=2.7%        Contact DBC Faculty

This table is generated using conservative estimates of maternal blood volume and Hct (5000 ml blood volume and 50% Hct). The formula to calculate RhoGAM dose is below:

   •(% HbF X 5000)/30 +1. Round appropriately and that is how many vials
     are recommended.
Test Limitations:
This testing does not detect fetal bleed in a Rh positive female or Rh negative fetus/infant.
Methodology:
Indicator cell rosette test for fetomaternal hemorrhage
Instructions:
If specimen is received in the laboratory greater than 24 hours from time of collection and has not been refrigerated, it will be rejected.
Sample Processing:
Invert tube gently several times to mix blood.
Label transport tube with patient last name, first name, identification number, date and time of collection.
Do Not Centrifuge.
Submit whole blood in original container.
Sample Storage:
Room temperature or refrigerate if stored overnight.
Transport Instructions:
Place requisition into outside pocket of bag.
Place specimen into zip-lock type bag, seal bag.
Place specimen into Styrofoam container, seal container.
Ship at room temperature.
CPT Code:
86905