Understanding Erythroblastosis Fetalis: Causes, Symptoms, and Treatment
Introduction
Erythroblastosis fetalis, also known as Haemolytic Disease of the Newborn, is a disease of the fetus and newborn child characterized by agglutination and phagocytosis of the fetus’ RBCs.
Cause
Rhesus incompatibility – Rh-positive child in an Rh-negative mother previously exposed to the Rh-positive blood through:
- Birth
- Miscarriage
- Abortion
- Blood transfusion
- Amniocentesis
- Chorionic villus sampling
Incidence
- Most likely in the 2nd to 4th pregnancy with an Rh+ child.
- Incidence rises progressively with subsequent pregnancies for Rh+ progeny.
Effects of the Mother’s Antibodies on the Fetus
After anti-Rh antibodies have formed in the mother, they diffuse through the placental membrane into the fetus’ blood. There:
- They cause agglutination of the fetus’ blood.
- Agglutinated RBCs hemolyze releasing hemoglobin into the blood.
- Fetal macrophages convert the hemoglobin into bilirubin which causes jaundice.
Clinical Picture of Erythroblastosis (Diagnostic Features)
- Jaundice as a result of the accumulation of bilirubin
- Anemia due to destruction of RBCs
- Nucleated blastic forms of RBCs present in fetal blood (hence the name Erythroblastosis fetalis)
- Enlarged liver and spleen as they try to replace hemolyzed RBCs
- Hydrops fetalis – edema of the fetus due to the accumulation of fluid
- Kernicterus – Brain damage due to precipitation of excess bilirubin in the neuronal cells
[Mnemonic – JANE H.K.]
Treatment of Neonates with Erythroblastosis Fetalis
- Replacement of the neonate’s blood with Rh-negative blood
Prevention of Erythroblastosis Fetalis
- Administration of Rh immunoglobulin (an anti-D antibody) to the expectant mother starting at 28 to 30 weeks of gestation
