Detection of fetal‐maternal hemorrhage in a mother with sickle trait and hereditary persistence of fetal hemoglobin

An Rh-negative term primigravida with sickle trait and hereditary persistence of fetal hemoglobin and an Rh-positive infant were evaluated postpartum for fetal-maternal hemorrhage (FMH) by the acid-elution test for fetal hemoglobin (HbF) cells. Using the acid-elution test, 100 percent of the cells contained HbF. The patient received one vial of Rh immune globulin and was discharged. This report illustrates that lack of specificity is a major problem of the acid-elution test for detection of fetal-maternal hemorrhage, due to its failure to differentiate true fetal Rh-positive cells from maternal Rh-negative HbF cells. Moreover, productivity studies suggest performance of agglutination tests such as the immune rosetting test is more convenient than performance of the acid-elution test to screen for FMH. The recently developed enzyme-linked antiglobulin test, however, may replace both of these procedures for detection of FMH.