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HelpTest Code LAB896 Fetal Screen
Useful For
The detection of Rh positive red blood cells in Rh negative mothers due to a feto-maternal hemorrhage.
At delivery, a variable volume of fetal blood enters the maternal circulation when the placenta separates from the uterine wall. In susceptible patients, this event may give rise to the production of maternal alloantibodies (Rh immunization). In most instances, Rh negative mothers delivering Rh positive infants can be protected from producing anti-D by the administration of Rhogam within 72 hours of delivery. A 300 ug dose of Rhogam is sufficient to suppress Rh immunization for no more than 30 mL of fetal whole blood that has entered the maternal circulation. The fetal screen test is used to detect a feto-maternal hemorrhage of an amount greater than that covered by the standard 300 ug dose of Rhogam.
Methodology
Erythrocyte Rosetting
Performing Laboratory
Bozeman Health Laboratory Services
Specimen Requirements
Specimen Type: EDTA whole blood
Container/Tube: Purple top or pink top (K2 EDTA)
Specimen Volume: 3 mL
Collection Instructions: Collect blood from mother at least 1 hour after delivery of all products of conception and collect as soon as possible thereafter. Do not centrifuge. Forward unprocessed whole blood promptly. Rhogam must be given within 72 hours of delivery.
Specimen Rejection: Gel tube
Specimen Transport Temperature
Ambient <24 hours/Refrigerated >24 hours
Specimen Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood EDTA | Ambient | 24 hours |
| Refrigerated | 48 hours |
Reference Values
Negative-One dose of Rhogam considered sufficient
If the fetal screen is positive, a Kleihauer-Betke test will be automatically reflexed to quantitate the volume of feto-maternal hemorrhage in post-partum D-negative women.
Day(s) Test Set Up
Monday through Sunday
Test Classification and CPT Coding
85461