Hemolytic Disease Of Newborn (HDN)

Question 1

Step 1

Answer 1

Before/during delivery, Rh-positive red blood cells from the fetus enter the blood of Rh-negative women through tear in placenta

Question 2

Step 2

Answer 2

Mother is sensitized to the arch antigen and produces anti-Rh antibodies

No effect on the first pregnancy

Question 3

Step 3

Answer 3

Rh-positive red blood cells cross the placenta, enter the maternal circulation, and stimulate the mother to produce antibodies against Rh-antigen

Antibody production is rapid, because mother has been sensitized to the Rh-antigen

Question 4

Step 4

Answer 4

The anti-Rh antibodies from the mother cross the placenta, causing agglutination and hemolysis of the fetal red blood cell and hemolytic disease of the newborn