Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
Prevention of Haemolytic Disease of the Fetus and Newborn (HDFN) in D Negative women to reduce the chances of forming immune anti-D antibodies (i.e. becoming sensitised).
Anti-D immunoglobulin prophylaxis is given routinely at 28-30 weeks gestation, within 72 hours following any sensitising events (an incident in which a fetomaternal haemorrhage may have occurred) and within 72 hours of delivery of a D positive baby.
Specimen container paediatric:
6mL K2 EDTA
Specimen container adult:
6mL K2 EDTA
Minimum volume paediatric:
2mL
Minimum volume adult:
6mL
Special requirements:
Test can be ordered via EPR PowerChart and taken with the BloodTrack bedside sample labelling system.
The Trust operates a zero tolerance policy. Deviation from Trust Sample Labelling Policy will result in the sample being rejected and a repeat requested.
Sample stability:
Short term storage: 24 hours at room temperature.
Long term storage: 7 days at 4-6°C
Transport requirements:
Sample should be transported to Laboratory Medicine Reception via GP courier, hospital air-tube system or hand delivered to maintain storage conditions. Samples must not be subjected to extreme hot or cold conditions prior to testing.
Availability:
24/7
Add on test:
Request for issue of anti-D must be discussed directly with the Transfusion laboratory.
RVI: 0191 2824435
Interpretation:
SUITABLE to receive prophylactic anti-D injection: Mother is D negative and DOES NOT have immune anti-D in her plasma after delivery of a D POSITIVE baby. Routine antenatal and postnatal prophylactic anti-D should always be given irrespective of additional anti-D immunoglobulin that may have been given due to a previous sensitising event. FMH estimation is performed to determine if any ADDITIONAL doses of anti-D prophylaxis are required; 1500IU Anti-D i.m is sufficient for up to 12mL FMH.NOT SUITABLE to receive prophylactic Anti-D injection: Mother is D positive Mother is D negative with known immune anti-D in her plasma after delivery of a D negative baby
Factors affecting result:
Anti-D immunoglobulin is not indicated: if the woman declines after discussion of the benefits and risks, if the woman has previously had cFFDNA testing for this particular pregnancy and the result states that the baby is D negative and chooses to decline with this information, if the woman is in labour, the patient is known to be sensitive to anti-D immunoglobulin or any of the products ingredients, the woman is D positive, the woman has immune anti-D.
Please refer to antenatal clinic guidelines for management in this situation.
For Suitability specimens: Insufficient, clotted or haemolysed specimens. Detection of previous prophylactic anti-D injections or other maternal atypical antibodies will require investigation and may extend turnaround times.
Other info:
Rhophylac anti-D injections must be kept refrigerated at 4-6oC.