Fetal Hemoglobin Determination for Fetomaternal Hemorrhage
Ordering Recommendation
Quantitative Flow Cytometry
1-2 days  
New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
Submit With Order
Specimen Required
Patient Preparation
Maternal, pregnant or post-partum whole blood.  
Lavender (EDTA) or pink (K2EDTA).  
Specimen Preparation
Transport 5 mL whole blood. (Min: 0.5 mL)  
Storage/Transport Temperature
Unacceptable Conditions
Frozen specimens. Clotted or hemolyzed specimens. Specimens older than 72 hours. Specimens from males or non-pregnant females.  
Ambient: 12 hours; Refrigerated: 72 hours; Frozen: Unacceptable  
Reference Interval
By report  
Interpretive Data
The performance characteristics of this test were determined by ARUP Laboratories, Inc.

See Compliance Statement B: www.aruplab.com/CS
Result Interpretation
% Fetal RBCs The fetal RBC percentage is directly measured by flow cytometry and gives the percentage of fetal RBCs in maternal circulation resulting from recent fetal-​maternal hemorrhage.  Post-​partum, some fetal cells are expected (0.04% plus or minus 0.024%, mean plus or minus SD).
Fetal Blood Volume Fetal blood volume is the volume of feto-​maternal hemorrhage and is calculated from the % Fetal RBCs by multiplying by 50, assuming a maternal blood volume of 5000 mL and a hematocrit of 50%.  Post-​partum, some feto-​maternal hemorrhage is expected (2.0 mL plus or minus 1.2 mL, mean plus or minus SD).
RhIg Required Given the delivery of an RhD+ fetus from an RhD-​ mother, the amount of IM RhIg (anti-​RhD immunoglobulin) required to avoid sensitization is 10 µg for each mL of feto-​maternal hemorrhage.
RhIg Vials Required Given the delivery of an RhD+ fetus from an RhD-​ mother, one (1) vial of RhD (300 µg vial administered IM) is recommended when the amount of RhD required is <300 µg.  From 300-​600 µg, 2 vials are recommended; from 600-​900 µg, 3 vials are recommended; from 900-​1200 µg, 4 vials are recommended; from 1200-​1500 µg, 5 vials are recommended and so forth.
This test should only be used to detect and quantify the extent of fetomaternal hemorrhage, in pregnant or post-partum women who need to be assessed for Rh immune globulin (e.g. RhoGAM®) or fetal-maternal bleeds. 

For routine fetal hemoglobin (Hb F) testing, please order Hemoglobin Evaluation with Reflex to Electrophoresis and/or RBC Solubility (0050610).
CPT Code(s)
Component Test Code*Component Chart Name
2001744Fetal Hgb - Fetal Blood Volume
2001745Fetal Hgb - RhIg Vials Required
2001746Fetal Hgb - RhIg Required
2001788Fetal Hgb - Percent Fetal RBCs
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • Fetal Hemoglobin
  • Fetal Maternal Bleed
  • Fetal Maternal Erythrocyte Distribution, Blood
  • Fetal-Maternal Erythrocyte Differentiation
  • Fetomaternal Bleed by Flow Cytometry (Blood)
  • Kleihauer Acid Elution (Fetal RBCs)
  • Kleihauer-Betke
  • Kleihauer-Betke Acid Elution for Fetal RBC Detection
  • Maternal Erythrocyte Diff
  • RhoGAM determination