What is erythroblastosis fetalis?

➢ Hemolytic Disease of the Newborn (HDNB) occurs when the mother has been sensitized to antigens on the infant's erythrocytes and makes IgG antibodies to these antigens. ➢ Sensitization of the Rh-mother to the Rh+ erythrocytes usually occurs during birth of the first Rh+ infant, when some fetal erythrocytes leak back across the placenta into the material circulation and are recognized by the material immune system ➢ If she becomes pregnant, and the father is Rh+ the fetus may be Rh+ as well. ➢ If so, the anti-Rh antibodies of the mother can cross the placenta and cause lysis of the fetal blood cells. ➢ The disease is hemolytic disease of newborns (erythroblastosis fetalis) Thus first child is unaffected while others are