Which is a common laboratory test used to assess fetomaternal hemorrhage in Rh-negative mothers?

The Kleihauer-Betke test is a significant laboratory test used to assess fetomaternal hemorrhage, particularly in Rh-negative mothers. This test specifically measures the amount of fetal hemoglobin present in the maternal circulation, which indicates whether any fetal blood cells have crossed into the mother's bloodstream.

In cases where Rh-negative mothers are carrying Rh-positive infants, the presence of fetal blood in the maternal circulation can lead to Rh sensitization, which has critical implications for future pregnancies. The Kleihauer-Betke test distinguishes fetal red blood cells from maternal red blood cells by identifying the fetal hemoglobin that remains intact and is resistant to lysis when subjected to certain conditions.

This information is crucial for determining the appropriate dosage of Rh immunoglobulin (RhoGAM) that the mother should receive to prevent Rh immunization. Knowing the extent of fetomaternal hemorrhage helps in making informed clinical decisions regarding maternal care and neonatal interventions.

The Rosette test is also a screening method for detecting Rh-positive fetal cells in the maternal blood but is less quantitative than the Kleihauer-Betke test. The direct Coombs test detects antibodies bound to red blood cells but does not specifically measure fetomaternal hemorrhage. The indirect