A newborn is left at the Emergency Department.The baby appears lethargic and slightly jaundiced.Laboratory work on the baby shows a positive DAT with polyspecific AHG and with anti-IgG.The hemoglobin is 7.3 gm/dl and the peripheral blood smear shows marked polychromasia, macrocytosis and increased numbers of nucleated RBCs.The bilirubin is 4.4 mg/dl.What do you suspect is the underlying cause of these results?

Question

Quizplus · Accepted Answer

The positive DAT with anti-IgG and the presence of nucleated red blood cells, marked polychromasia, and macrocytosis on the peripheral blood smear are indicative of hemolytic disease of the fetus and newborn (HDFN). The presence of jaundice and a high bilirubin level further support this diagnosis. ABO HDFN is less likely given the positive DAT with anti-IgG, and normal postnatal findings would not be consistent with the symptoms and lab results seen in this case. Autoantibodies from the mother would cause a positive DAT, but would not explain the other findings. Hence, the most likely cause is Rh HDFN due to the presence of anti-IgG on the DAT.

A Newborn Is Left at the Emergency Department