Question

how did the discovery of the rhesus factor affect society?
o more patients died from having a transfusion with the wrong rhesus factor.
o new treatments during pregnancy could prevent harm to the developing child.
o less donated blood could be used in the treatment of patients.
o the number of blood types was reduced by half.

Explanation:

The rhesus factor is an important aspect in blood - related medical scenarios. When a Rh - negative mother is pregnant with a Rh - positive fetus, without proper treatment (which became possible after the discovery of the rhesus factor), there can be complications like hemolytic disease of the newborn. New treatments (such as Rh immunoglobulin injections) during pregnancy were developed based on the understanding of the rhesus factor, which can prevent harm to the developing child.

• Option 1: The discovery of the rhesus factor actually reduced the number of deaths from wrong - rhesus - factor transfusions as proper matching could be done.
• Option 3: The discovery of the rhesus factor allowed for more appropriate use of donated blood (by considering the rhesus factor in addition to ABO type), so more blood could be used effectively (after proper typing), not less.
• Option 4: The number of blood types was not reduced by half. Blood types are classified based on ABO and rhesus factor (e.g., A +, A -, B +, B -, AB +, AB -, O +, O -), so the number of blood - type combinations increased when rhesus factor was considered.

Answer:

New treatments during pregnancy could prevent harm to the developing child.