This study evaluated fetomaternal hemorrhage (FMH) in 343 postpartum patients who required prophylaxis of Rh alloimmunization with anti-D immunoglobulin. The rosette test was applied to screen for patients needing quantitative determination of fetal blood transferred from the maternal circulation, which was then measured by the Kleihauer-Betke test (K-B). The rosette test was positive in 22 cases (6.4%). In five of these cases, K-B did not show fetomaternal hemorrhage (a 1.45% false-positive rate for the rosette test), and in one case the test was inconclusive. There were 8 cases with FMH < 10ml (2.3%), 6 cases with FMH from 10 to 30ml (1.7%), and two cases with FMH > 30ml (0.58%), requiring a supplementary dose of anti-D. The study concludes that following the rosette test, additional evaluation of FMH using a quantitative test was unnecessary in 93.6% of the cases.
Fetal Erythroblastosis; Fetomaternal Transfusion; Rho(D) Immune Globulin