Fetal Hemoglobin Determination for Fetomaternal Hemorrhage
Ordering Recommendation

Detect and quantify the extent of fetomaternal hemorrhage in pregnant or postpartum women. Assess the need for Rh immunoglobulin (eg, RhoGAM) for fetomaternal hemorrhage.

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
ARUP Consult®
Disease Topics
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.

% Fetal RBCsThe 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 VolumeFetal 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 RequiredGiven 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 RequiredGiven 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.

Compliance Statement B: This test was developed and its performance characteristics determined by ARUP Laboratories. The U.S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

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).
Component Test Code*Component Chart NameLOINC
2001744Fetal Hgb - Fetal Blood Volume55730-6
2001745Fetal Hgb - RhIg Vials Required1313-6
2001746Fetal Hgb - RhIg Required55731-4
2001788Fetal Hgb - Percent Fetal RBCs55729-8
* 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