ABO/Rh

Blood Type (ABO & Rh)

Hemograma completo

Última revisión: 7 de abril de 2026. Enfoque de fuentes: contexto estándar de interpretación de laboratorio, material médico de referencia y orientación clínica o de salud pública cuando corresponde.

¿Qué es Blood Type (ABO & Rh)?

Blood typing determines an individual's ABO blood group (A, B, AB, or O) and Rh (D) status (positive or negative), the two most clinically important red blood cell antigen systems. The ABO system is defined by the presence or absence of A and B carbohydrate antigens on the red blood cell surface: type A has A antigens, type B has B antigens, type AB has both, and type O has neither. Individuals naturally produce antibodies against the ABO antigens they lack—anti-B in type A, anti-A in type B, neither in type AB, and both anti-A and anti-B in type O.

The Rh system is the second most important blood group system, with the D antigen being the most immunogenic. Individuals who express the D antigen are Rh-positive (~85% of the population), while those lacking it are Rh-negative. Unlike the ABO system, Rh antibodies are not naturally occurring—anti-D develops only after exposure to Rh-positive blood through transfusion or pregnancy. ABO and Rh typing is essential for safe blood transfusion, organ transplantation, and prenatal care. Incompatible transfusion can cause acute hemolytic reactions that are potentially fatal.

Por qué importa

Accurate blood typing is essential for patient safety. ABO-incompatible transfusion can trigger a severe acute hemolytic reaction due to preformed anti-A or anti-B antibodies, causing complement-mediated intravascular hemolysis, disseminated intravascular coagulation, renal failure, and death. Rh typing is critical in women of childbearing age—an Rh-negative mother carrying an Rh-positive fetus can develop anti-D antibodies that cross the placenta and destroy fetal red blood cells, causing hemolytic disease of the fetus and newborn. Preventive anti-D immunoglobulin has dramatically reduced this condition.

Rangos de referencia normales

Grupo	Rango	Unidad
Type O	~44% of population	(most common)
Type A	~42% of population
Type B	~10% of population
Type AB	~4% of population	(least common)
Rh-positive	~85% of population
Rh-negative	~15% of population

Los rangos de referencia pueden variar entre laboratorios. Compara siempre tus resultados con los rangos proporcionados por tu laboratorio.

Qué significan los niveles altos de ABO/Rh

Causas comunes

Not applicable—blood type is a genetic classification, not a value that is high or low

Posibles síntomas

Blood type itself does not cause symptoms

Qué hacer: Blood type is an inherent genetic trait and is neither high nor low. The clinical significance of your blood type relates to transfusion compatibility, organ donation matching, and pregnancy management. Know your blood type and inform healthcare providers, especially in emergencies.

Qué significan los niveles bajos de ABO/Rh

Causas comunes

Not applicable—blood type is a genetic classification

Posibles síntomas

Blood type itself does not cause symptoms

Qué hacer: See above—blood type is not measured on a scale. If you are Rh-negative and pregnant, discuss anti-D immunoglobulin prophylaxis with your obstetrician. If you are type O-negative (universal donor for red blood cells) or AB-positive (universal plasma donor), consider becoming a blood donor.

¿Cuándo se recomienda la prueba de ABO/Rh?

Before any blood transfusion
During pregnancy (first prenatal visit)
Before surgery where transfusion may be needed
For organ and tissue transplant matching
Blood donor screening
Newborn blood typing when mother is Rh-negative

Preguntas frecuentes

For red blood cell transfusion: type O-negative is the universal donor (compatible with all types), and type AB-positive is the universal recipient. Ideally, patients receive type-specific blood. For plasma transfusion, compatibility is reversed: AB plasma is the universal donor, and type O recipients can receive any plasma type. Rh-negative patients should receive Rh-negative blood to prevent anti-D sensitization.

If an Rh-negative mother carries an Rh-positive baby, fetal red blood cells that enter the maternal circulation during pregnancy or delivery can stimulate the mother's immune system to produce anti-D antibodies. In subsequent pregnancies, these antibodies can cross the placenta and destroy the fetus's red blood cells, causing hemolytic disease of the newborn. Anti-D immunoglobulin (RhoGAM) given at 28 weeks and after delivery prevents this sensitization.

In extremely rare cases, blood type can appear to change after a bone marrow or stem cell transplant, where the recipient's blood type may convert to the donor's type. Some diseases (leukemia, infections) can transiently alter antigen expression. However, for the vast majority of people, blood type is fixed for life and determined by inherited genes from both parents.

Biomarcadores relacionados

DATDirect Coombs Test IATIndirect Coombs Test HgbHemoglobina

Referencias y enfoque de revisión

Las páginas del glosario de biomarcadores son explicaciones educativas y deben interpretarse junto con los rangos de referencia y comentarios proporcionados por tu laboratorio y tu profesional de salud. Para conocer nuestros estándares editoriales y proceso de revisión, consulta nuestra Política editorial y nuestro Proceso de revisión de contenido.

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Aviso médico: Esta información es solo educativa y no sustituye el consejo, diagnóstico ni tratamiento médico profesional. Los rangos de referencia pueden variar entre laboratorios. Consulta siempre a tu profesional sanitario para interpretar tus resultados concretos.