This 35-year-old gravida 4 para 1 + 2 woman, was seen by her gynecologist when she was 8 weeks pregnant. Her first preg

[answerhappygod]

This 35-year-old gravida 4 para 1 + 2 woman, was seen by her
gynecologist when she was 8 weeks pregnant. Her first
pregnancy 4 years ago was unremarkable. The patient reported that
her second and third pregnancies had resulted in a stillbirth
at 36 weeks and a spontaneous abortion at 10 weeks of
gestation. Her medical history revealed no history of blood
transfusions. She remembered being vaccinated for rubella. Her
medical records had been destroyed in a fire at the clinic.
Repeat blood grouping and Rh testing and an irregular antibody
screen were ordered.
The patient returned in 2 weeks for a repeat anti-D titer. titer
had risen to 1:16 At 17 weeks' gestation, an amniocentesis was
performed. Severe hemolysis was demonstrated, and an intrauterine
transfusion of the fetus was carried out using fresh, washed,
cytomegalovirus screening test-negative, group 0, Rh(D)-negative
blood. Because of the continuing risk to the fetus, a cesarean
section was performed at 36 weeks' gestation. On delivery, the baby
was noted to be jaundiced and pale. The first of three exchange
transfusions was performed. Phototherapy was also used to degrade
the bilirubin deposited in the skin. The baby made an uneventful
recovery with no signs of kernicterus and was discharged from the
hospital 5 days after birth.
1. What is the mechanism of HDFN?
2. What prophylactic measures are used to prevent HDFN caused by
the D-antigen?