A Novel Method of Detecting
Maternal Fetal Hemorrhage
Michael V. Muench, M.D.
School of Medicine, University of Maryland, Baltimore


Maternal trauma requiring medical attention complicates 6-7% of pregnancies. Trauma in pregnancy is unique: even trivial injury may provoke preterm labor and its cascade of serious complications for both mother and fetus. Traumatic placental injury can result in transplacental hemorrhage (TPH, also called fetomaternal hemorrhage.) The Kleihauer Betke (KB) test detects fetal red blood cells in the maternal circulation, providing evidence of placental damage. A positive KB appears to be a risk factor for preterm labor. The principle application of KB testing has been to detect smaller volumes of TPH in Rh-negative women, who should receive prophylaxis against Rh-sensitization in such circumstances. Although the KB has been clinically useful in detecting large episodes >30ml of TPH requiring maternal treatment with Rh immune globulin, it is laborious and suffers from subjectivity and imprecision. The recent advent of monoclonal antibodies to fetal hemoglobin with the utilization of flow cytometry has allowed for better detection of TPH. Unfortunately, flow cytometry is not available on a 24-hour basis. We hypothesize monoclonal antibodies can be utilized in an automated hematological analyzer (Abbott Celldyn 4000) to detect TPH as effectively as flow cytometry.