Early identification in maternal blood of fetal sex in the presence of fetal DNA from previous pregnancies.

摘要

The presence of cell-free fetal DNA in maternal plasma allows for the noninvasive identification of fetal sex. It was recently suggested, however, that fetal-cell DNA can persist in the maternal circulation from one pregnancy to the next , thereby severely hampering prenatal diagnostic analysis of fetal DNA from maternal plasma.A method for clearing fetal-cell DNA from a previous pregnancy in maternal plasma was developed to facilitate the identification of cell-free fetal DNA from the current pregnancy.