Use

Determines a patient’s ABO blood group (A, B, AB, or O) and Rhesus (Rh) type (positive or negative), which is essential for compatibility in blood transfusion, managing pregnancy to prevent hemolytic disease of the fetus and newborn, and other clinical and emergency care situations. Specifically in pregnancy, identifying Rh (D) status helps assess the need for Rh immune globulin administration to prevent sensitization and HDFN. Quest’s protocol also classifies weak D results as Rh negative to ensure appropriate prophylaxis. ([questdiagnostics.com](https://www.questdiagnostics.com/healthcare-professionals/clinical-education-center/faq/faq111?utm_source=openai))