Background: Infants with severe hemolytic disease of the fetus and newborn often require 1 or multiple intrauterine transfusions to treat fetal anemia. Intrauterine transfusions may have an inhibiting effect on fetal and neonatal erythropoiesis.
Objective: To quantify the effect of 1 or multiple intrauterine transfusions on the fetal erythropoiesis by assessing the fetal reticulocyte counts in a population with severe hemolytic disease of the fetus and newborn.