Test Directory

Test Code
PREN
Test Name
Prenatal ABO/RH Type and Screen
CPT Codes
86850, 86900, 86901
Included Tests
  • ABO
  • Rh (D)
  • Antibody Screen

Reflexed when appropriate:

  • Antibody Identification
  • Phenotype Antigen Test
  • Direct Coombs Test
  • Eluate
  • Antibody Titer
  • EGA Treatment
  • Human Erythrocyte Antigen (Genotype)
  • IGG IGM Subclass
  • Adsorption
  • DTT
Expected Turnaround Time
1 - 3 days
Clinical Utility

A screen for red cell antibodies is performed and if positive antibody identification procedures are performed to identify antibody specificity and to eliminate the presence of other underlying alloantibodies. The antibody screening test may not detect antibodies to low incidence antigens or antibodies which have undetectable titers by routine techniques.

IgG alloantibodies reacting at 37°C and/or in the antiglobulin phase are generally considered clinically significant in transfusion and in hemolytic disease of the newborn (HDN).

IgM alloantibodies reacting at room temperature and below are generally considered clinically insignificant in transfusion and in hemolytic disease of the newborn. Weak low titer antibodies or antibodies to low incidence antigens may not be detectable at the time of testing.

Specimen and Container Info

Preferred Specimen Type: Whole Blood

Preferred Collection Container: 1 Pink Top (EDTA)

Alternate Collection Container: 2 Lavender Top (EDTA)

Desired Specimen Volume: 6 mL

Minimum Acceptable Volume: 3 mL

Collection Instructions

The specimen tube shall be properly labeled with the following 3 independent identifiers for inpatients and outpatients:

  1. Patient's full name
  2. Date of birth
  3. Medical record number

The labels shall also include the following verifiers:

  1. Date and time of collection
  2. Initials/tech code of phlebotomist

Exception Criteria:

  • Trauma -ED patient: Patients with unknown name and date of birth, medical record number and temporary name are acceptable.
  • Good Shepherd Rehab: Typenex band ID is used as an additional patient identifier
Processing and Submission Instructions

Non-hospitalized patients: Submit specimen with a completed Blood Bank Requisition (LAB-04) Form. Transfusion and pregnancy history within the last 3 months should be included.

Transport Instructions

i. Transport to the laboratory at room temperature within 24 hours of collection

ii. Transport to the laboratory refrigerated past 24 hours of collection

Stability Requirements

Room Temperature

24 hours

Refrigerated

7 days

Causes for Rejection
  • Mislabeled
  • Insufficient volume
  • Inappropriate specimen type
Methodology
Hemagglutination
Reference Intervals
  • Negative antibody screen: No unexpected red cell antibody detected
  • Positive antibody screen: Presence of a red cell antibody
Performing Location
Cedar Crest Hospital
Testing Schedule
Routine, daily
Reflex Tests
%ABI, %DBS, %DIG, %ELU, ADPT, C3D, DTT, DTTAS, EGA, MGNT1