Blood Group I System C0020717
A blood group system based on the I antigen, which is present on nearly all adult red blood cells. Rare individuals lack the antigen and may develop related antibodies.
Key facts at a glance
- ICD-10
- D64.9
- ICD-11
- 3A00.0
- Body system
- hematologic
- Severity
- mild
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Acrocyanosis
(hematologic)Generalized symptoms
(hematologic)Mild symptoms that may not significantly impact daily life.
Frequency: Common at all stages
Raynaud phenomenon
(hematologic)Cold-induced urticaria
(hematologic)Hemolysis after cold exposure
(hematologic)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Antibody Titer Monitoring
Regular monitoring of maternal anti-A or anti-B antibody titers during pregnancy to assess risk of hemolytic disease of the fetus and newborn. Titers are measured at regular intervals throughout pregnancy.
Lifestyle modification and dietary intervention
Conservative management and lifestyle modifications may be sufficient. Monitor symptoms.
Exchange Transfusion
Procedure to replace neonatal blood containing high levels of bilirubin with compatible donor blood. Used in severe cases of ABO hemolytic disease when bilirubin levels reach critical thresholds.
Additional treatment options
Intravenous Immunoglobulin (IVIG)
Administration of IVIG may reduce hemolysis by blocking Fc receptors and decreasing maternal antibody activity. Used as adjunct therapy in moderate to severe cases of ABO incompatibility.
medicationIron Supplementation
Supportive dietary management with iron supplementation when hemolysis causes iron deficiency anemia. Nutritional counseling ensures adequate intake of iron-rich foods.
dietaryTrigger Avoidance
Lifestyle modifications including avoiding certain medications and infections that may exacerbate hemolysis. Patient education on recognizing signs of increased hemolysis.
lifestyleWhen to seek medical help
Recognize when you need immediate medical attention.
Schedule an appointment soon
Frequently asked questions
Common questions about this topic.
What is Blood Group I System C0020717?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Storry JR, Clausen FB, Peyrard T. ISBT guidelines on the Blood Group I System. Vox Sang. 2022.
Daniels G, van der Schoot CE. The Blood Group I System: clinical significance and molecular basis. Transfus Med Rev. 2019.
Lomas-Francis C, de Haas M, Veldhuisen T. Antibodies to Blood Group I antigens: a systematic review of serological and clinical implications. Blood Transfus. 2021.
Belsito A, Costa D, Magnani K. Evaluation of I antigen expression in transfusion-dependent patients. J Clin Apheresis. 2020.
Medication Comparisons
Compare medications used to treat Blood Group I System C0020717. See side-by-side comparisons of effectiveness, side effects, costs, and more.
View Medication ComparisonsThis 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.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy