Hemolytic Diseae of Newborn Flashcards
Fetal and Neonatal Erythropoiesis
Fetal Sites of Hematopoiesis
- Yolk sac, Liver, Bone Marrow
- Hgb F
Newborn RBC
45-70 day life
53-90% Hgb F (high O2 affinity)
Newborn RBC at 40 weeks
Cord Blood Hgb = 19 +/- 2.2 g/dl
Infant Size
Smaller transfusion volume
Hypovolemia
Not enough volume, not right blood pressure
Leads to decreased O2 in tissues and acidosis
Transfuse “whole blood” - transfuse pRBC O cells using AB plasma
Cold Stress
0% fat
MUST use blood warmers
Newborn Immunologic Status
Maternal Antibodies
- Baby has mom IgG, transfuse with antigen negative blood
Graft vs Host - give irradiated pRBCs
Metabolism Concerns
K+ Levels and 2,3 DPG Levels
Need Fresh Blood
CMV
MUST give true CMV negative blood
Decreased RBC Survival
Increased RBC production
Nucleated RBCs
Erythroblastosis fetalis
Hct - 15% or less
Size of Liver and Spleen
Increased
Anemia
Hydrops fetalis
Severe anemia
Cardiac Failure and Death
Likely Requires Intrauterine Transfusion
Three Main Categories of HDN
ABO HDN
Rh HDN
HDN due to other antibodies
ABO HDN
Maternal IgG ABO Antibody (Type O mothers IgG)
Less Severe
Rh HDN
Maternal IgG Anti-D
Most Severe
HDN Due to other antibodies
Maternal IgG Antibody
Maternal Immunization for ABO HDN
Naturally occuring antibodies
A or B infants with Group O Mother
- Tyoe AB mother do NOT cause HDN
Maternal Immunization Rh Immune Globulin (Rhogam)
IgG Anti-D
Administered at 28 weeks
Administered Post Partum
Mimics ABO Incompatibility Effect (may cause pos DAT on baby)
Prenatal Testing on Mother
ABO/Rh - includes weak D testing
Antibody Screen
- Antibody Identification
- Antibody Titer (if High Risk)
- 1:32 titer or higher associated with severe HDN
Other Prenatal Testing
Father’s Antigen Status
28 week Prenatal Testing
For Rh Negative Mothers
- ABO/Rh
- Antibody Screen
- Rh Ig
Monitor of HDN Severity
Amniocentesis
- Rh neg mothers with high-titer anti D or previously affected pregnancies
- LEvel of bile pigment in amniotic fluid - Optical Density 450nm
PUB Sample Testing (Percutaneous Umbilical Blood)
Very risky procedure
Umbilical Vein
ABO/Rh
DAT
Cord Hgb
Bilirubin
CBC
Antigen Typing
Fetal Lung Maturity
Consideration of Early Delivery
Ratio of Lecithin to Sphingomylin (L/S Ratio)
If fetus <29 weeks or severe HDN indicated
L/S Ratio >2.0:1
Mature
L/S Ratio 1.5:1
40% respiratory distress
Physician and mom call if should deliver early
L/S Ratio <1.5:1
70% respiratory distress
Choose to do intrauterine transfusion
Intrauterine Transfusion
Risky Procedure
RBCs infused through fetal abdominal wall or umbilical vein
Repeated with small volumes until delivery
Intrauterine Transfusion Products
Fresh RBCs (<7 days old); Hct = 80%
Washed RBCs
CMV Negative or Leukodepleted
Irradiated
Group O, Rh Negative reconstituted with AB plasma
- MUST be negative for antigen corresponding to mom Ab
Post Delivery Testing
ABO/Rh
DAT
ABO/Rh Post Delivery
No reverse Group
Weak D Testing
DAT Post Delivery
anti IgG AHG
Positive - elute Ab and identify
ID Ab in maternal or cord serum
Exchange Transfusion Helps
Remove antibody-coated RBCs
Controls anemia
Removes Bilirubin
- Prevents Kernicterus
Blood Products for Exchange Transfusion
Group O RBCs
Must be compatible with maternal antibody
Rh compatible with mother and infant
Complications of Exchange Transfusion
Cardiac (if go to fast)
Vascular-Mechanical (destroy too many cells)
Infections
Hematologic-Coagulation
Immunologic (GVHD)
Hypothermia
Post Delivery Testing Mother
ABO/Rh (weak D)
IAT
FMH Screen (possibly)
Kleihauer-Betke Stain
FMH Screen
Performed on D negative mom
Must be anti-D negative
Kleihauer-Betke Stain
Determine amount of fetal blood mom was exposed to
Hgb F resistant to acid denaturation
RhIg Calculation
(% fetal cells x 50)/30
First dose of RhIg
28 weeks
Rh Negative mother
No Immune Anti D
RhIg After Delivery
Within 72 hours
Rh Negative Mother
No Immune Anti D
Rh Positive Baby
Group O Mother
Group O, A, B Baby
pRBCs Group O
Group A Mother
Group O or B Baby
pRBCs Group O
Group A Mother
Group A or AB Baby
pRBCs Group A or O
Group B Mother
Group O or A
pRBCs Group O
Group B Mother
Group B or AB Baby
pRBCs B or O
Group AB Mother
Group A Baby
pRBCs Group A or O
Group AB Mother
Group B Baby
pRBCs Group B or O
Group AB Mother
Group AB Baby
pRBCs Group AB, A, B, or O
