75373-1

LOINC code 75373-1 identifies "Erythrocytes.fetal/2000 erythrocytes in Blood by Kleihauer-Betke method". A blood test to measure the amount of fetal hemoglobin (Hb F) transferred from a fetus to a mother's bloodstream, usually performed on Rh negative mothers to determine the required dose of immune globulin (RhIg) to inhibit formation of Rh antibodies in the mother and prevent Rh disease in future Rh positive children. In a newborn, half or more of the hemoglobin is fetal hemoglobin. The concentration of Hb F falls rapidly and by the age of one to two years it is less than 1%. [Miale, J.B., Laboratory Medicine Hematology, 6th ed. C.V. Mosby, St. Louis (MO) 1982, p 608.)] The Association of Blood Banks recommends counting adult and fetal erythrocytes in as many fields as required giving a total count of at least 2000 cells. Then calculate percent fetal cells in the total counted. [Technical Manual. American Association of Blood Banks, 16th ed. Arlington (VA) 2008, pp 936-937] This term was created for, but not limited in use to, the Fetal Hemoglobin Sure-Tech test kit. This assay is similar to term 48556-5 except that 2000 cells are counted rather than 1000 cells.

This code measures Erythrocytes.fetal/2000 erythrocytes in Bld. It belongs to the HEM/BC class in the LOINC classification.

LOINC (Logical Observation Identifiers Names and Codes) is a universal standard for identifying laboratory and clinical observations. It is maintained by the Regenstrief Institute and used worldwide for health data exchange.