Erythroblastosis fetalis (also called hemolytic disease of the fetus and newborn) is a serious pregnancy complication caused by blood type incompatibility between a mother and her fetus, most often due to Rh factor differences. It can lead to severe anemia, jaundice, and even life-threatening conditions in the fetus or newborn if untreated.

🌍 Definition

• Erythroblastosis fetalis: An immune-mediated condition where maternal antibodies attack fetal red blood cells.
• Most common cause: Rh incompatibility (Rh-negative mother, Rh-positive fetus).
• Other causes: Less common antigen incompatibilities (Kell, Duffy, Kidd, etc.).

🔑 Causes & Mechanism

• Rh-negative mother + Rh-positive fetus → maternal immune system produces antibodies against fetal red blood cells.
• Antibodies cross the placenta and destroy fetal cells (hemolysis).
• This leads to anemia, forcing fetal organs (liver, spleen, bone marrow) to overproduce immature red cells (erythroblasts).

📚 Symptoms

• In the fetus:
  • Anemia (pale skin, lethargy).
  • Hydrops fetalis (severe swelling, fluid buildup in organs).
• In the newborn:
  • Jaundice (yellowing of skin/eyes within 24 hours).
  • Rapid heartbeat, poor feeding, enlarged liver/spleen.
  • Severe cases → kernicterus (bilirubin buildup in brain, causing seizures or brain damage).

🛠 Diagnosis

• Prenatal: Blood type testing, antibody screening, ultrasound for fetal anemia/swelling, amniocentesis for bilirubin levels.
• Postnatal: Cord blood testing, bilirubin levels, complete blood count.

💉 Treatment

• During pregnancy:
  • Intrauterine blood transfusions if severe anemia develops.
  • Early delivery if fetus is at risk.
• After birth:
  • Phototherapy for jaundice.
  • Blood transfusions or exchange transfusions.
  • IV immunoglobulin (IVIG) to reduce red cell destruction.

🛡 Prevention

• Rh immunoglobulin (RhIg, RhoGAM®) given to Rh-negative mothers during pregnancy and after delivery prevents antibody formation.
• Routine prenatal blood type testing makes the condition highly preventable in regions with good medical care.

✨ Summary

Erythroblastosis fetalis is a preventable but potentially fatal condition caused by maternal-fetal blood type incompatibility. With modern prenatal care and Rh immunoglobulin, severe outcomes are rare, but untreated cases can lead to anemia, jaundice, hydrops fetalis, and even death.

Sources: Cleveland Clinic – Erythroblastosis Fetalis Children’s Hospital of Philadelphia – Hemolytic Disease of the Newborn Apollo Hospitals – Erythroblastosis Fetalis Overview