A nation-wide fetal RHD screening programme for targeted antenatal and postnatal anti-D

In the Netherlands, since 1 July 2011, both antenatal anti-D immunoprophylaxis (1000 IU in the 30^th week of gestation) and postnatal prophylaxis (1000 IU) is administered to only those women for whom a fetal RHD typing, performed in week 27 of pregnancy, predicts the presence of a D-positive child. The fetal RHD screening is part of the antenatal Screening Programme for Infectious diseases and Erythrocyte immunisation (PSIE), offered to all pregnant women early in pregnancy at their first antenatal visit, preferably before 12 weeks of gestation. Currently, the compliance to the fetal RHD screening programme and the performance of the fetal RHD typing test is evaluated in a nation-wide study. At the start of the programme, it was determined that the number of false negative test results should be below 0·25%. In the first seven months after introduction of the fetal RHD screening programme, the number of false-negative results was below the critical threshold and the number of false positives around 1·1%. The compliance to the programme was in this period >95%. Our first analysis confirms that, in a centralised setting, it is possible to guide both antenatal and postnatal anti-D immunoprophylaxis by fetal RHD screening in maternal blood obtained at 27 week of gestation. The current analysis, however, is based on the cord blood samples received by Sanquin only. A longer period of nation-wide evaluation of the fetal RHD screening programme, including all (also locally typed) cord blood serology results obtained in a one-year time period, will provide insight in the robustness of the fetal RHD screening programme.