Overview
Antibodies from an Rh negative mother may enter the blood stream of her unborn Rh positive infant, damaging the red blood cells (RBCs). The infant responds by increasing RBC production and sending out immature RBCs that still have nuclei. This photograph shows normal RBCs, damaged RBCs, and immature RBCs that still contain nuclei.
Review Date 1/1/2025
Updated by: Charles I. Schwartz, MD, FAAP, Clinical Assistant Professor of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, General Pediatrician at PennCare for Kids, Phoenixville, PA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.