Infants with hemolytic disease of the fetus and newborn (HDFN) caused by Rh incompatibility are often born with high iron levels that can last through their first year of life, according to a study published recently in Transfusion.
Researchers found that giving these infants iron supplements too soon could do more harm than good, especially for those who received transfusions before birth.
This study followed 56 infants diagnosed with Rh isoimmunization and fetal anemia. Nearly two-thirds (62%) had undergone one or more intrauterine transfusions to treat anemia before delivery, while 38% received exchange transfusions after birth. At birth, 95% of the babies had elevated serum ferritin, a measure of stored iron, with a median level of 846 mcg/L. Even at 12 months, 46% still had above-normal levels of ferritin.
“An alternative strategy could be individualized iron supplementation based on serum ferritin,” the authors wrote.
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Researchers measured ferritin and hemoglobin levels at birth and at 3, 6, 9 and 12 months. Median ferritin steadily declined from 846 mcg/L at birth to 77 mcg/L at one year, but infants who received intrauterine transfusions maintained higher ferritin throughout infancy compared with those who did not. About 55% of the infants needed top-up transfusions, and only 30% eventually required iron supplementation when ferritin dropped below 30 mcg/L.
These results suggest that most infants with Rhh-mediated HDFN are born with iron overload due to ongoing red blood cell destruction and transfusions. Elevated iron can strain the liver and other organs if left unchecked. However, no infants in the study showed signs of organ damage or required chelation therapy, which is used to remove excess iron.
Based on these results, the authors recommend that doctors delay routine iron supplementation in infants who received intrauterine transfusions until at least 12 months of age. Instead, they should base treatment on regular monitoring of ferritin and hemoglobin levels.
For parents, this means that iron supplements, which are often viewed as beneficial, could be harmful in babies recovering from Rh hemolytic disease. Careful follow-up with pediatricians and regular blood testing can help prevent unnecessary treatments and ensure safe recovery from this potentially serious condition.
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