Postpartum anti-D: can we safely reduce the dose?
OBJECTIVE
To assess the potential for dose-reduction of prophylactic anti-D postpartum.


METHODS
Retrospective audit of fetomaternal haemorrhage (FMH) quantitation by flow cytometry.


METHODS
5148 consecutive Rhesus D-negative women aged 15-45 years who had FMH estimation by flow cytometry at a central laboratory in Western Australia in the 65 months between 1 August 1999 and 31 January 2005.


METHODS
Quantitation of FMH volume for adequate prophylactic anti-D administration in a timely fashion.


RESULTS
90.4% (4651/5148) of the women had an FMH volume of 1.0 mL or less of Rh D-positive red cells, and 98.5% (5072/5148) had a volume of less than 2.5 mL. Only 0.4% of cases had an FMH volume of 6.0 mL or greater (range, 6.0-92.4 mL).


CONCLUSIONS
This large retrospective audit shows that a currently available dose of 250 IU (50 mg) of anti-D would have been sufficient for 98.5% of the 5148 Rh D-negative women. On the basis of this evidence, a reduction in the recommended routine postpartum dose of anti-D from 625 IU to 250 IU when flow cytometric quantitation for FMH is available should be considered. Adopting such a strategy would ensure the ongoing provision of a valuable human blood product currently in limited supply.
Augustson
Bradley M
BM
PathWest Laboratory Medicine WA, Perth, Western Australia, Australia. bradley.augustson@health.wa.gov.au
Fong
Elizabeth A
EA
Grey
Dianne E
DE
Davies
Janine I
JI
Erber
Wendy N
WN
D000293:Adolescent; D000328:Adult; D001682:Biological Availability; D001811:Blood Volume Determination / Q000379:methods; D004305:Dose-Response Relationship, Drug; D004899:Erythroblastosis, Fetal / Q000517:prevention & control*; D005260:Female; D005331:Fetomaternal Transfusion / Q000097:blood*; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007231:Infant, Newborn; D007518:Isoantibodies / Q000008:administration & dosage* / Q000097:blood*; D008485:Medical Audit; D008875:Middle Aged; D049590:Postpartum Period / Q000097:blood* / Q000187:drug effects; D011247:Pregnancy; D012189:Retrospective Studies; D018029:Rho(D) Immune Globulin; D016896:Treatment Outcome
D007518:Isoantibodies; C061961:RHO(D) antibody; D018029:Rho(D) Immune Globulin