OBJECTIVES

: To prevent hemolytic disease of the fetus and newborn, routine antenatal care in many countries involves RhD immunoglobulin (anti-D) being offered to all RhD negative pregnant women. Recent advances in non-invasive cell-free fetal DNA testing of the RHD gene has made targeted administration of anti-D possible to women with a baby predicted to be RhD positive. Our objective was to undertake a cost-effectiveness analysis and budget impact analysis of non-invasive fetal RHD genotyping to target pregnant women for antenatal anti-D prophylaxis therapy.

METHODS

: A decision-analytic model was constructed to compare RHD testing and targeted anti-D prophylaxis, with current universal anti-D prophylaxis among pregnant women with RhD negative blood type. Model estimates were derived from national perinatal statistics, published literature, donor program records and national cost sources. One-way sensitivity analyses addressed the uncertainty of variables on the main findings.

RESULTS

: The unit cost for RHD genotyping was estimated at AU$45.48 (US$31.84). The ‘mean cost per healthy baby’ was AU$7,495 (US$5,247) for universal prophylaxis and AU$7,471(US$5,230) for targeted prophylaxis. The findings were sensitive to the unit costs of anti-D 625 IU (AU$59-$88)(US$41-62), the genetic test (AU$36-$55)(US$25-39) and, packaging/transport costs of the samples for testing (AU$15-40, US$11-28 per sample). With RHD genotyping, 13,938 women would avoid antenatal anti-D prophylaxis at a total cost-savings to the National Blood Authority of AU$2.1 million (US$1.5 million) per year. To the health system, net cost savings of AU$159,701 (US$111,791) per year (0.05%) were predicted for total healthcare costs.

CONCLUSIONS

: Routine RHD genotyping for RhD negative women during pregnancy would produce substantial cost-savings for the Australian National Blood Authority while being cost-neutral to the whole health system. Notwithstanding the vulnerable supply of donor plasma and other ethical and health concerns, RHD genotyping is an economically sound option for Australia.