Foetale Resus-D-typering toegevoegd aan prenatale screening op infectieziekten en erytrocytenimmunisatie

Objective: Investigation of the accuracy and national implementation of foetal RhesusD typing (fRhD), introduced in 2011 for RhDnegative pregnant women. Design: Descriptive, national study. Method: Results of fRhD in pregnant women in the first year after implementation were compared to results from cord blood RhD typing of the child. Results: 0.05% of the fRhD results was false negative (9/18.383; 95% CI: 0.020.09), and 0.85% was false positive (157/18.383; 95% CI: 0.731.00). fRhD was incorrectly omitted in fewer than 1% of pregnant women. In 96.1% of the pregnant women, antenatal administration of antiD prophylaxis was recorded. Recording of postnatal antiD administration turned out to be lower (92%), but locally recorded data showed that postnatal antiD was omitted in fewer than 2% of cases. Conclusion: The percentage of false negative fRhD was statistically significantly lower (p < 0.05) than the critical limit of 0.25% determined beforehand by the Programme Committee of the Dutch Antenatal Screening Programme for Infectious Diseases and Erythrocyte Immunisation. The percentage of false positive fRhD was considered acceptable, and implementation of fRhD was more or less complete. Routine RhDtyping on cord blood was therefore omitted from January 2013. Antenatal and postnatal antiD administration is now specifically indicated for RhDnegative pregnant women when fRhD is positive, thus saving about 10,000 unnecessary antenatal antiD administrations per year. RhDtyping on cord blood is now performed only if the RhD blood type of the child of a RhDnegative mother is unknown at delivery, if a positive fRhD was found for multiple births, and in exceptional situations, e.g. if fRhD typing is not possible due to a rare genetic variation. Conflict of interest and financial support for this article: C.P.B. van der Ploeg and M. de Haas received payment from the RIVMCentrum voor Bevolkingsonderzoek (Dutch National Institute for Public Health and the Environment, Centre for Population Screening) for monitoring the "Antenatal Screening Programme for Infectious Diseases and Erythrocyte Immunisation".