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Test Code FBSC Fetal Blood Screen

Useful For

Detecting the presence of Rh(D)-positive fetal red cells in the sample of an Rh(D)-negative maternal patient and need for more than 1 vial of Rh immune globulin. The test is used for screening Rh(D)-negative mothers who deliver an Rh(D)-positive infant or who are greater than 20 weeks EGA (estimated gestation age) and at risk for fetal maternal hemorrhage from a potential sensitizing event (e.g. abdominal trauma, miscarriage, external cephalic version, fetal demise).   This test is not required for routine antenatal Rh Immune Globulin administration at 28-30 weeks EGA.   This is a qualitative test only.  If positive, a quantitative test (Kleihauer-Betke stain) will be reflexively performed to determine the extent of fetomaternal hemorrhage and appropriate dosage of Rh immune globulin.

Synonyms/Keywords

Fetal maternal bleed (qualitative), Fetal Bleed Screen

Specimen Requirements

Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
No Whole blood EDTA Lavender Top Tube (LTT)
2.0 mL 0.5 mL NA

Collection/Processing Instructions

Postpartum specimen can be drawn one hour post-delivery or with next AM lab order.

Specimen Stability Information

Specimen Type Temperature Time
Whole Blood Refrigerate Perform testing within 48 hours of collection

Rejection Criteria

Gross hemolysis

Test Information

Fetal Blood Screens are performed on all postpartum Rh(D)-negative mothers who deliver an Rh(D)-positive infant.  Testing also performed on Rh(D)-negative mothers greater than 20 weeks EGA who are exposed to potential sensitizing event and at risk for fetomaternal hemorrhage (e.g. abdominal trauma, miscarriage, external cephalic version, in-utero therapeutic intervention, fetal death).   Transfusion Service will order FBSC on postpartum hospitalized patients based on infant ABO/Rh typing results, i.e. when infant is Rh(D)-positive or Rh type of infant cannot be determined.   If FBSC is positive, a Kleihauer-Betke stain will be reflexively ordered and performed to quantify the fetomaternal bleed and determine the necessary dosage of Rh immune globulin for prevention of anti-D alloimmunization.

Reference Range Information

Performing Location Reference Range
All Performing Sites Negative

Marshfield Labs Performing Department

Marshfield Labs Transfusion Services

Performing Information

Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
MMC-Rice Lake
 Monday through Sunday 2-4 hours Hemagglutination
Marshfield Monday through Sunday 2-4 hours Hemagglutination 
MMC-Beaver Dam
 Monday through Sunday
 2-4 hours
 Hemagglutination

CPT Codes

CPT Modifier
(if needed)		 Quantity Description Comments
85461  

Outreach CPT Codes

CPT Modifier
(if needed)		 Quantity Description Comments
85461  

Ordering Applications

Ordering Application Description
Centricity Fetal Blood Screen
Cerner None