3. INTRODUCTION
ABO-Hemolytic disease of newborn
25% of pregnancies
HDN develops only in 1/10 such offsprings
O group mother and A/B group fetus
Female>male
OA>OB
Cause-reaction of maternal anti-A/B to antigen present
on RBC of fetus or newborn
IgG antibodies cross the placenta
4. BLOOD TYPES
ABO system in 1990
A,B,AB,O
Central principle is ANTIGENS
Isoantibodies against isoantigens
Important for transfusion
6. ABO on 9q34 -glycosyltransferase
A- N-acetyl galactosamine
B- galactose
H on 19
H antigen-precursor
Antigens contained in food,bacteria and vaccines
7.
8. MODERATING FACTORS
Mild nature and low incidence of ABO-HDN accounts
for
low antigenicity of AB factors
wide distribution
fewer antigen sites on preterm RBC
9. DIFF B/N ABO & RH
INCOMPATIBILTIES
May occur in first born
Increasing frequency of disease in subsequent
pregnancies is generally not present
The subsequent babies may be more effected or less
effected or even spared
10. HS AND ABO-HDN
Increased osmotic fragility, autohemolysis,
splenomegaly in both
But autohemolysis is not corrected by glucose as in HS
Family history,long-term course,MCHC differentiate HS
from ABO-HDN
11. DIAGNOSIS(suspected)
Antenatally –
Past history of ABO-HDN in previous sibling
Titer of anti-A/anti-B in mother is >1:64
Postnatally –
Early onset of jaundice <24hrs
A/B group baby of O mother
Mild splenomegaly
Anemia – usually absent
12. DIAGNOSIS(laboratory)
Serum bilirubin
Reticulocytosis
Spherocytosis
Fragility of RBC
Confirmation of antibodies-eluted serum
Direct coomb’s test
Maternal IgG antibodies in ADCC assay
Detection of antigen density on RBC
High titres of anti-A/B hemolysins-in maternal serum
13. Start intensive phototherapy if bilirubin exceeds
10mg/dl at 12hrs
12mg/dl at 18hrs
14mg/dl at 24hrs
15mg/dl at any time
Exchange transfusion-if it reaches 20mg/dl
MANAGEMENT
16. SUMMARY
INCIDENCE
O group mother and A/B group fetus
Co-dominant inheritance
HS and ABO-HDN
Diagnosis
Management –phototherapy and exchange transfusion
17. REFERENCES
Manual of neonatal care-CLOHERTY
Care of new born-MEHERBAN SINGH
HARRISON’S principles of internal medicine