alloimmune neonatal neutropenia

neutropenia in the newborn due to in utero incompatibility between its immunoglobulin G antigens and those of the mother's blood; the mother's blood produces IgG antineutrophil antibodies that cross the placenta and sensitize fetal neutrophils. Affected infants may have fever, pneumonia, septicemia, and other infections that can be fatal. The condition eventually resolves itself as the infant's immunoglobulin replaces that from the mother.