Ultra-early Identification of Fetal Chromosomal Characteristics From Extravillous-trophoblast Cells

During pregnancy, biological screening for genetic diseases of the fetus cannot be implemented before the 11th week of amenorrhea whatever the technique used. This delay is long and distressing, particularly for people at high risk of transmission of genetic diseases. The presence of extravillous trophoblast cells to the cervix of the pregnant woman from the 7th week, accessible by a cervicovaginal smear non-invasive, represents new biological material representative of the fetal genome. This project aimed at evaluating the performance of a method for analyzing these trophoblast cells extra-villous at the start of pregnancy. The investigators want to evaluate performance analytical aspects of this method, that is to say, verifying that the genetic information resulting from these cells correspond to those of the fetus.