Le diagnostic prénatal non invasif (DPNI) sur sang maternel

摘要

Circulating fetal DNA in maternal plasma and serum was first demonstrated by Lo et al. in 1997 and has become a useful tool for prenatal diagnosis less than five years later. There is more and more evidence that trophoblatic cells act as the major source of this circulating fetal DNA. Contrary to fetal cells analysis in maternal blood which requires isolation and enrichment procedures, fetal DNA analysis is relatively easy to perform with the use of realtime PCR. Non invasive fetal sex and fetal RHD genotype determination are, to date, the two main clinical indications. Those newly offered possibilities have changed the management of pregnant women who are carriers for X-linked genetic disorders; prenatal diagnosis by choriovillous sampling could only be performed for male fetuses avoiding an unnecessary risk of fetal loss for female fetuses. Moreover, fetal RHD genotyping, by maternal blood analysis, could be useful in RHD negative women at risk of RHD immunization in order to adapt prophylactic anti-D immunoglobulin injection to avoid unnecessary administration in case of a RHD negative fetus. Aneuploidies detection is now possible using free fetal DNA in maternal blood. Trisomy 21, 18 and 13’s diagnosis is presently offered in various countries. First as a screening test for high risk patients selected by the classical screening test, it has recently been offered to general population. The extremely rapid technological advances in this field and the ability to perform this test by sending blood abroad render urgent implementing those tests in France in order to ensure equal access to health care for patients.