Understanding Your Rh Antibody Titre Test
What It Is: The Rh Antibody Titre Test measures the concentration of Rh antibodies in your blood. These antibodies are produced by the immune system in response to exposure to Rh antigens found on the surface of red blood cells. This test is particularly important during pregnancy to assess the risk of Rh incompatibility between the mother and the fetus.
Why It's Important: Rh antibodies can cross the placenta and attack the red blood cells of an Rh-positive baby if the mother is Rh-negative. This can lead to hemolytic disease of the newborn (HDN), a serious condition that requires prompt medical attention.
Role of Rh Antibodies: Rh antibodies are produced when an Rh-negative individual is exposed to Rh-positive blood, either through blood transfusion, pregnancy, or other means. The presence of these antibodies can cause the immune system to attack Rh-positive red blood cells.
How Rh Antibodies Work:
Initial Exposure: The immune system produces Rh antibodies when first exposed to Rh-positive blood.
Subsequent Exposures: If the immune system encounters Rh-positive blood again, it quickly produces a large number of antibodies, leading to hemolysis (destruction of red blood cells).
What to Expect During the Test:
Blood Sample Collection: A healthcare professional will draw a small sample of your blood, usually from a vein in your arm.
Laboratory Analysis: The sample is then sent to a lab where the level of Rh antibodies is measured.
Interpreting the Results:
Normal Rh Antibody Levels: Indicates no Rh antibodies are found, suggesting no Rh incompatibility.
High Rh Antibody Levels: Indicates the presence of Rh antibodies, which may suggest Rh incompatibility. Levels greater than 1:4 indicate Rh alloimmunization, with higher titers needing further monitoring and intervention.
Why Your Doctor Might Order This Test:
Diagnosing Rh Incompatibility: To check for Rh incompatibility between an Rh-negative mother and an Rh-positive fetus.
Monitoring Pregnancy: To assess the risk of hemolytic disease of the newborn (HDN) and take necessary precautions.
Evaluating Blood Transfusion Compatibility: To ensure safe blood transfusions for individuals with Rh-negative blood.
Symptoms That Might Prompt This Test:
Jaundice (yellowing of the skin and eyes) in the newborn
Anemia in the newborn
Enlarged liver or spleen in the newborn
Fluid buildup in the baby's body (hydrops fetalis)