•Stillbirth assessment should, in all
instances, incorporate testing of maternal blood for
evidence of massive fetal-maternal hemorrhage.
•Blood drawing can be done pre- or postpartum
at the convenience of the care provider and the
mother; only if cesarean section is anticipated is it
important to draw the sample prior to delivery.
•Standard Kleihauer-Betke testing in any
experienced laboratory is sufficient. (In this test,
by acid elution the mother's red blood cells become
very pale while fetal cells, which contain a
different form of hemoglobin, remain stained. Simple
comparative counts allow an estimate of whether a
significant fetal-maternal transfusion occurred.)
•In those with positive tests (25% or more of
estimated fetal blood volume lost), follow up testing
(at a postpartum check) should be done to rule the
possibility of a false positive because of a process,
such as e.g. sickle cell trait, in the mother which
causes persistent elevation of fetal hemoglobin.
For a complete discussion of the justification for
testing for FMH and methods of estimating the percentage
of fetal blood volume lost, see WiSSPers, volume 1, number
1.
