Assay

Kleihauer

Key Words

Kleihauer, FMH, foetal, maternal, foetomaternal, haemorrhage

Specimen Collection

3.4ml EDTA. Sample should be taken at least 30 minutes after the sensitising event. The samples should arrive promptly enough in the laboratory to allow for testing and reporting of results so that appropriate anti-D prophylaxis can be administered within 72 hours of the sensitising event. If an FBC is also requested, an additional sample bottle is required for the Kleihauer. The two tests cannot be run on the same sample.
Delivery Kleihauers require a 7.5ml and 3.4ml from both mother and cord of each baby.

Turnaround time

Testing is performed twice daily Monday-Friday and once on Saturday morning.

Test indications

For RhD-negative pregnant women, to determine if any foetal blood has crossed the placenta into maternal blood after a potential sensitising event, in order to calculate how much prophylactic anti-D is required to prevent sensitisation.

Interferences

Haemolysed or lipaemic samples may not be able to complete testing, whereupon new samples will be required. Samples must be received as whole blood; any samples which have been spun will not be suitable for testing.

Reference Range

N/A

Minimum retesting interval

Testing should be performed at each sensitising event that occurs after 20 weeks gestation, as well as at delivery. For continuous vaginal bleeding during pregnancy, contact the haematology consultant for advice regarding the frequency of ongoing foeto-maternal haemorrhage estimation and anti-D administration.