In a case of suspected fetomaternal hemorrhage, what test should be performed?

In suspected cases of fetomaternal hemorrhage, the Kleihauer-Betke test is the appropriate test to perform. This test is specifically designed to detect fetal red blood cells in a maternal blood sample, allowing for the quantification of the amount of fetal blood that has entered the maternal circulation. This is clinically important as it helps determine the severity of the hemorrhage and informs treatment decisions, such as the need for Rh immunoglobulin administration in Rh-negative mothers to prevent Rh sensitization.

The other options, while relevant in various clinical contexts, do not provide the specific information needed for a suspected fetomaternal hemorrhage. For example, type and screen is crucial for preparing blood transfusions but does not measure fetal-maternal blood exchange. Coagulation studies assess the mother’s coagulation status, which may be important in different scenarios but is not directly linked to evaluating fetomaternal hemorrhage. A hematocrit test measures the proportion of red blood cells in the blood, which may reflect anemia but does not specifically identify the presence or extent of fetal blood in the maternal circulation.