HDFN

Question 1

HDFN

Answer 1

When mother has an antibody that crosses the placental barrier, is specific for an antigen on the fetal RBCs and capable of destroying those cells
anti-D is most severe form
ABO is most common form

Question 2

Fetomaternal Bleed

Answer 2

Fetal RBCs enter mom’s circulation
During subsequent pregnancies, unexpected IgG antibody crosses placenta and attaches to fetal red cell antigens causing hemolysis

Question 3

Pathophysiology

Answer 3

Accelerated red cell destruction in utero leads to increased production of fetal RBCs
Leads to increased numbers of nucleated RBCs in the fetal circulation
Severe cases can result in generalized edema and severe anemia of the fetus, bilirubinemia, brain damage, death
Treat with exchange transfusion of the newborn and phototherapy

Question 4

Liley Graph

Answer 4

Amniotic fluid is subjected to spectrophotometric scan at steadily increasing wavelengths so that the change in optical density at 450 nm can be calculated
Zone 1: observe fetus for stress
Zone 2: moderate disease
Zone 3: severe problems

Question 5

Doppler Flow Studies Ultrasound

Answer 5

Middle cerebral artery (MCA) of the fetus
Degree of fetal anemia can be assesed by measuring the peak velocity of blood flow in the MCA
Reliable indicator of fetal anemia
No risk of injury or death to the fetus or mother

Question 6

Intrauterine Transfusion

Answer 6

Indications: correct fetal anemia, 24 to 26 week gestation
Blood component: Group O negative red cells with Group AB plasma to a 75/80% hematocrit, hemoglobin S negative, CMV negative, irradiated RBCs, less than 7 days old
Methods: intraperitoneal or intravascular

Question 7

Rh Immune Globulin

Answer 7

RhIg/Rhogam
Concetrate of IgG anti-D developed from pools of human plasma
Prevent mom from making immune anti-D by suppression of immune response
Full dose: 300 mg, counteracts 15 mls packed RBCs or 30 mls of whole blood

Question 8

Rosette Test

Answer 8

Screening test to detect the presence of Rh positive RBCs in the circulation of Rh person
Qualitative

Question 9

Kliehauer Betke

Answer 9

Quantitative test for presence of fetal red cells in mothers circulation
(# fetal cells / 2000 adult cells) x 100 = % fetal cells in maternal circulation
% fetal cells x 50 = number of mls of fetal cells
# mls of fetal bleed / 30 = # vials of RhIg required (plus 1)
Use 15 if packed RBCs, 30 if whole blood