Useful For

At birth or upon abortion there may be a transfer of blood from fetus to mother. This may be significant in cases of Rh (+) positive fetus or an Rh (-) negative mother. The fetal maternal RBC distribution detects the presence of fetal cells in the maternal blood and gives a rough estimate of the amount of fetal maternal bleed and thus the amount of Rh immune globulin to be given postpartum. Notes: 1)One 300 ug dose of Rh immune globulin is given for each 15 ml of estimated fetal RBC. 2)To determine the number of vials of Rho Immune Globulin needed to protect against immunization: % Fetal Cells Volume of FMH * < 0.3 15 ml 0.3 - 0.89 29.5 ml 0.9 - 1.49 59.8 ml 1.5 – 2.09 89.5 ml 2.1 - 2.69 119.5 ml 2.7 – 3.29 149.5 ml 3.3 – 3.89 179.5 ml * The range provides for the poor accuracy and precision of the acid elution test. These recommendations are base upon 1 vial needed for each 15 ml rbcs or 30 ml whole blood. Blood bank determines vials necessary.