Apport du génotypage fœtal non invasif sur sang maternel pour la prise en charge des allo-immunisations antiérythrocytaires et la prévention Rhésus

摘要

Using a genetic amplification technique, noninvasive foetal erythrocyte genotyping is based on the possibility of identifying the genes carried by the foetus, and which are not shared with the mother, in the DNA extracted from her plasma. This technique is a huge breakthrough in the management of situations at risk of immunisation and known foeto-maternal incompatibilities. It enables: 1) the administration of anti-D immunoglobulins to be avoided for RhD-negative women who are pregnant with a foetus who is also RhD-negative and thus eliminates the risk of immunisation; 2) foeto-maternal RhD incompatibility situations to be identified or eliminated and justifies the specific monitoring of repeated anti-D antibody titres/dosages and the monitoring of middle cerebral artery peak velocity; 3) a foetomaternal incompatibility situation in the Kell system to be identified or eliminated. Techniques are progressing year on year; they are becoming more and more reliable and the use of these tests for all immunised pregnant women who are RH:-1 (RhD-negative) or KEL:-1 (Kell negative) is seen on a daily basis in maternity units. The Haute Autorité de santé (HAS) has positively assessed the benefit of the use of non-invasive foetal RHD genotyping, however this procedure is yet to feature in everyday nomenclature. The GENIFERh study, including data that is still being analysed, will enable medical and economic aspects to be determined for the various non-invasive foetal genotyping strategies available.