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22624 Fetal Blood Screen

Fetal Blood Screen
Test Code: FBSC
Synonyms/Keywords
​​​Fetal maternal bleed (qualitative), Fetal Bleed 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.
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
Performing Laboratory 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
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​
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
85461   ​
Synonyms/Keywords
​​​Fetal maternal bleed (qualitative), Fetal Bleed Screen
Ordering Applications
Ordering Application Description
​Centricity ​Fetal Blood Screen
​Cerner ​None
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
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
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
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.
Reference Range Information
Performing Location Reference Range
All Performing Sites Negative​
For more information visit:
Performing Laboratory 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
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
85461   ​
For most current information refer to the Marshfield Laboratory online reference manual.