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 therapy (eg, RhoGAM) in Rh negative mothers.

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 the 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). For accurate calculation of RhIG dosage that includes maternal height and weight, please refer to the CAP RhIG calculator ( or to the most recent AABB Technical Manual.

Compliance Statement B: For laboratory developed tests not using a RUO kit, and for FDA approved, cleared or 510(k) exempt assays with alterations. 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).
Hotline History
View Hotline History
Component Test Code*Component Chart NameLOINC
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