Which trio of components is typically included in a standard prenatal workup?

• A. ABO, Rh, antibody screen
• B. DAT, crossmatch, infectious disease screen
• C. Hgb, bilirubin, LDH
• D. Platelet count, coagulation studies, reticulocytes

Answer: (A)

The essential idea is to establish blood-group compatibility and detect maternal antibodies that could affect the fetus. ABO typing identifies the mother’s and fetus’s blood groups, which helps anticipate any ABO-related risks during pregnancy. Rh typing determines if the mother is Rh-negative, which is important because Rh sensitization can occur if the fetus is Rh-positive; this leads to hemolytic disease of the fetus and newborn if not managed, hence the use of Rh immunoglobulin when indicated. The antibody screen looks for antibodies in the mother’s serum that could react with fetal red cell antigens beyond ABO and Rh. If an alloantibody is present, that guides monitoring and potential interventions to protect the fetus.

Tests like the direct antiglobulin test on maternal blood, crossmatching for a planned transfusion, or routine infectious-disease screening can occur in pregnancy, but they are not part of the standard baseline triad used specifically to assess transfusion compatibility and alloimmune risk. The other options focus on neonatal hemolysis markers or general bleeding risk, which are not the standard trio for initial prenatal screening.