Test Code FHGB Fetal hemoglobin

Important Note

Routine orders are held for flow cytometry method performed Monday through Friday 8:00am - 3pm. Saturday 8am to 1pm.

Specimen and Container/Tube

Specimen Type: Whole blood

Preferred Specimen: lavender top

Other Acceptable specimens: not applicable

Specimen Stability

Storage Temperature	Stability
Room temperature (20 - 25°C)	24 hours
Refrigerated (2 - 10°C)	48 hours
Frozen (-20°C)	not acceptable

Collection Instructions

Collect specimen per standard laboratory collection procedures.

Specimen Handling and Transport Instructions

UCMC Onsite Instructions: Collect specimen per standard collection procedure and send to laboratory immediately.

UCMC Offsite and UC MedLab Outreach Instructions: Collect specimen per standard collection procedure and send to laboratory immediately. Specimens must be received within 24 hours. If transport is delayed, store the sample in a refrigerator.

Rejection Criteria

Common specimen rejected situations include: incorrect specimen type, insufficient volume, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits.
Frozen or heated specimens will be rejected
Clotted or quantity not sufficient specimens are not suitable for testing and will be rejected

Reference Values

Analyte	Age	Sex	Reference Range
Percent fetal red cells	< 2 years	Male and female	>90.00%
Percent fetal red cells	> 2 years	Male and female	< 0.10%
F cells percent	All	Male and female	< 5.8%

Critical Values

Not applicable

Clinical Indications

Fetal maternal hemorrhage
RhIG dose
Other - Distribution of fetal hemoglobin in adult RBCs

Test Components

Flow Cytometry: Percentage of fetal red cells and "F' cells, in peripheral blood sample.

Kleihauer Betke: Percentage of fetal cells and adult cells in peripheral blood sample.

CPT Codes

CPT codes

LOINC Codes

FHGB

Methodology

Flow cytometry or Kleihauer-Betke acid slide elution method.

Kleihauer Betke Method will be performed outside of flow cytometry hours for STAT orders.

Routine orders are held for flow cytometry method performed Monday through Friday 8:00am - 3pm. Saturday 8am to 1pm.

Volume

Preferred Volume: 4.0 mL

Minimum Volume: 1.0 mL

Turnaround Time

Turnaround times are relative to the time the specimen is received in the test laboratory.

STAT Turnaround Time: 60 minutes

Routine Turnaround Time: 24 hours

Testing Schedule:

Flow cytometry method performed Monday through Friday 8:00am - 3pm. Saturday 8am to 1pm.