Genetic testing for RhD and RhCE blood group alleles (qualitative)
This test checks for specific genetic variations in your Rh blood group system, which can affect blood compatibility during transfusions or pregnancy.
["Understanding your Rh blood group alleles helps ensure safe blood or pregnancy care."]
Key facts at a glance
- LOINC
- 42325-1
- Short code
- RHD + RHCE alleles Geno Bld/T
- Synonyms
- RHD + RHCE alleles Geno Bld/T
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 0
- Ref high
- 5
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- CPT
- 82378
- SNOMED
- 394995008
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Doctors may order this test if you have a history of complications during pregnancy (such as miscarriage or stillbirth), require blood transfusions, or if your blood type is unclear. It helps determine whether you carry certain Rh alleles that could impact compatibility with donated blood or fetal development.
What to Expect Before the Test
No special preparation is needed. A blood sample will be taken from a vein in your arm, similar to a regular blood draw. The sample is then analyzed in a lab to detect specific genetic markers.
What the Results Mean
Results will identify which RhD and RhCE alleles you possess. This information helps healthcare providers determine your Rh blood type (e.g., Rh-positive or Rh-negative) and whether you are a carrier of certain alleles that may require additional precautions during pregnancy or blood transfusions.
Common Conditions Linked to These Alleles
The Rh blood group system includes multiple alleles, and variations can influence compatibility risks. For example, certain RhCE alleles may be associated with increased sensitivity to Rh-immune globulin (Rhogam) during pregnancy or affect blood type consistency in future pregnancies.
Reference range
Non-smokers: <2.5 ng/mL; Smokers: <5.0 ng/mLN/A
No special preparation required. For PSA, avoid sexual activity for 24-48 hours before the test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily used to confirm or clarify Rh blood group status, which is critical for safe blood transfusions and prenatal care. Rh-negative individuals who are RhD-negative may need Rhogam during pregnancy to prevent hemolytic disease of the fetus or newborn. The RhCE alleles can also influence how your body responds to certain blood products or medications.
Short name
Rh Blood Group Allele Test
Frequently asked questions
What does a positive or negative result mean for my Rh blood type?
Will this test change how I receive blood transfusions or take prenatal care?
Can this test be used to predict pregnancy complications?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy