The DAT result of Baby Boy Jones indicates a positive test. What does this imply about the mother's eligibility for RhIg?

The correct implication is that a positive Direct Antiglobulin Test (DAT) in Baby Boy Jones indicates that his red blood cells are coated with antibodies, likely due to Rh incompatibility if the mother is Rh negative. In this situation, the baby's Rh type cannot be accurately determined because the presence of antibodies can interfere with the testing process.

If antibodies are attached to the baby's red cells, the test used to identify whether the baby is Rh positive could yield misleading results. As a result, the mother's eligibility for Rh immunoglobulin (RhIg) cannot be assessed without verifying the baby's Rh status, making it unclear whether she would need to receive RhIg to prevent potential sensitization in any subsequent pregnancies.

The mother's Rh status must also be considered, but the key issue arises from the interference of the positive DAT, which complicates the determination of the baby's blood type. Hence, while the mother's Rh status is certainly relevant to the overall assessment, the question specifically hinges on the ambiguity introduced by the positive DAT, leading to the conclusion that the baby's Rh type cannot be determined.