Year: 2026 | Month: May | Volume: 16 | Issue: 5 | Pages: 160-164
DOI: https://doi.org/10.52403/ijhsr.20260519
Late Hypoproliferative Anemia of Hemolytic Disease of Newborn (HDN) - Post Rhesus Isoimmunisation - A Case Report
Shreeprada Sharma1, Sonal Rajmane1, Mohnish Darshan1, Harshitha Reddy1, Amber Kumar1, Girish Chandra Bhatt1, Shikha Malik1
1Department of Pediatrics, All India Institute of Medical Sciences, Bhopal, Madhya Pradesh, India.
Corresponding Author: Dr. Amber Kumar
ABSTRACT
Introduction: Hemolytic disease of the fetus and newborn (HDFN) is caused by maternal IgG–mediated destruction of fetal erythrocytes, most commonly due to RhD incompatibility, and can present with a spectrum ranging from fetal anemia to neonatal hyperbilirubinemia. Late-onset anemia, a common complication, typically occurs between 2–6 weeks of age. We report a case of late onset hyporegenerative anemia secondary to Rhesus isoimmunization.
Case Description: A two-and-a-half-month-old female infant presented with progressively increasing pallor, initially noticed over the face subsequently involving the upper and lower extremities over a period of 3 days. She was born late preterm to an Rh-negative mother with isoimmunization and had required intrauterine transfusions, followed by postnatal phototherapy and IVIG for hyperbilirubinemia. On follow-up, she was found to have severe isolated anemia (Hb 5.5 g/dL) with reticulocytopenia and mild indirect hyperbilirubinemia, suggestive of late onset hyporegenerative anemia secondary to hemolytic disease of the newborn. A positive indirect Coombs test supported ongoing immune-mediated pathology. The infant was managed with packed red cell transfusions, showing hematological improvement on follow-up, and is under close monitoring.
Discussion: Hemolytic disease of the fetus and newborn (HDFN), most commonly due to RhD alloimmunization, results in immune-mediated destruction of fetal erythrocytes and may lead to complications ranging from fetal anemia to neonatal hyperbilirubinemia and kernicterus. Late-onset anemia is a frequent complication, particularly in infants who undergo intrauterine transfusions, typically presenting between 2–6 weeks of age and resolving by 3 months. It is classified into hyporegenerative and hemolytic types, with the former characterized by reduced erythropoiesis and low reticulocyte counts. Management of hyperbilirubinemia includes intensive phototherapy and exchange transfusion, while anemia is treated with packed red cell transfusions. Adjunct therapies such as erythropoietin and nutritional supplementation have limited and variable benefits. Close follow-up with serial hematological monitoring is essential to guide management and ensure recovery.
Conclusion: This case underscores the need for heightened awareness of late-onset hyporegenerative anaemia in infants with Rh isoimmunization. This atypical delayed presentation at 10 weeks highlights the variable clinical spectrum of late hyporegenerative anemia and the need for continued clinical suspicion beyond the usual age range. Bone marrow aspiration is indicated in atypical neonatal anemia with persistent reticulocytopenia or suspected alternative marrow pathology.
Key words: Hyporegenerative marrow, hemolytic disease of newborn, intrauterine transfusion