Answer:
Immunoglobulin G (IgG) molecules
Step-by-step explanation:
Erythroblastosis also called as Hemolytic disease of fetus and the newborn, is a type of alloimmune condition that advance in the peripartum fetus, when the lgG molecule (antigen released and created by plasma B cells) produced by mother body passes through the wall of the placenta. These antibodies attack antigens the RBCs in fetal circulation resulting in the breaking down and also the destroying of the cells (hemolysis). Reticulocytosis and anemia can be developed by the fetus. This fetal disease ranges from mild to very severe (even death).