Add-on
Rh Factor: Positive or Negative and Why It Matters
All NiaHealth tests are processed in Canadian-certified labs, which are highly trusted by the medical community for their accuracy and reliability. Blood and urine samples are collected by licensed medical professionals and processed using state-of-the-art equipment. NiaHealth is SOC2 Type 2 certified.
What is it?
“Rh factor” refers to the Rh blood group system antigen D on red blood cells. If this D antigen is present, a person is Rh-positive; if absent, the person is Rh-negative. The Rh system comprises many antigens (C, c, D, E, e are the five main ones), but the D antigen is the most immunogenic and clinically significant Rh factor in blood typing.
Why it matters
Rh factor status is crucial in pregnancy and transfusion medicine. An Rh-negative mother can form antibodies against an Rh-positive fetus’s red cells, leading to hemolytic disease of the fetus/newborn, which can cause anemia and jaundice in the baby. In transfusions, Rh-negative patients should generally receive Rh-negative blood to prevent alloimmune reactions; if an Rh-negative individual is exposed to Rh-positive blood, they may develop anti-D antibodies that cause dangerous hemolysis in future transfusions or pregnancies. Preventative measures (like Rh immune globulin) are used to avoid Rh sensitization in Rh-negative pregnant women.
Reference ranges
Rh factor is reported as either Rh-positive or Rh-negative. There are no reference ranges and no optimal range.
Myle, Akshay K., and Ghanim H. Al-Khattabi. “Hemolytic Disease of the Newborn: A Review of Current Trends and Prospects.” Pediatric Health, Medicine and Therapeutics, vol. 12, 2021, pp. 491–498.
Westhoff, Connie M. “The Rh blood group system in review: a new face for the next decade.” Transfusion, vol. 44, no. 11, 2004, pp. 1663–1673.
This information is educational and does not replace medical advice, diagnosis, or treatment. Your results should be interpreted with a qualified healthcare professional in the context of your health history.
