An easy-to-use method for detecting fetal hemoglobin--a test to identify bleeding from vasa previa.

Background: Vasa previa is a rare but potentially dangerous fetal condition that may occur during pregnancy. Ideally, all cases such cases are detected antenatally, but many present as late vaginal hemorrhaging. At the current time, there is no test for fetal hemoglobin (HbF) in general use.